The Palmaria 155 mm self-propelled howitzer was developed from 1977 by Oto Melara specifically for export and first production vehicles followed in 1982. The first customer to order the Palmaria was Libya, with an order for 210. Nigeria ordered 25 during 1982 and a further 20 Palmaria turrets were ordered by Argentina to be fitted on locally built TAM medium tank chassis. These were completed late in 1986 by which time final deliveries had been made to Libya and Nigeria.

Argentina has built lengthened TAM medium tank chassis that have been fitted with the turret of the Palmaria. The Argentine system is called the VCA 155. This has been produced in small quantities and is now operational in Argentina. Available details of this are given in a separate entry.

In 1990, Oto Melara completed a further batch of 25 155 mm Palmaria systems for an undisclosed customer. Some sources indicate that this was a repeat order from Nigeria.

Production of the Palmaria 155 mm self-propelled howitzer has now been completed. Oto Melara is now building the German Krauss-Maffei Wegmann 155 mm/52 calibre PzH 2000 self-propelled artillery system under licence for the Italian Army.

The chassis of the Palmaria 155 mm self-propelled howitzer is of all welded steel armour which provides the occupants with protection from small arms fire and shell splinters. Many of the automotive components of the Palmaria 155 mm self-propelled howitzer are also used in the Oto Malara OF-40 Main Battle Tank. Total of 36 of these were built for the United Arab Emirates plus a small number of armoured recovery vehicles on a similar chassis. These OF-40 MBTs have been phased out of front line service and are now being converted into heavy infantry fighting vehicles under the leadership of the Belgian company of Sabiex. The driver is seated at the front of the hull on the right side and is provided with a single-piece hatch cover and three day periscopes, the centre one of which can be replaced by a passive periscope for night driving. The other four crew members, commander, gunner, charge handler and magazine operator, are seated in the aluminium turret in the centre of the hull.

The commander is seated in the right forward part of the turret which has eight day periscopes for all-round observation and a single-piece hatch cover that opens to the rear. There are two external stowage racks at the rear of the turret. In either side of the turret there is a large rectangular hatch, the left one opening to the rear and the right one opening forwards. A 7.62 or .50 (12.7 mm) M2 HB anti-aircraft machine gun can be mounted on the roof for anti-aircraft defence and four 76 mm smoke grenade dischargers are mounted either side of the turret firing towards the front.

The vehicle has an auxiliary power unit to supply the hydraulic and electric power required to operate the turret, consisting of a diesel engine driving through a gearbox, a generator and a hydraulic pump. Standard equipment includes an NBC system, an automatic fire-extinguishing system, bilge pumps and an emergency escape hatch in the floor.

The Oto Melara-designed 155 mm barrel is 41 calibres long, is fitted with a fume extractor and a muzzle brake and is loaded semi-automatically. Using the semi-automatic loading system, the howitzer can fire one round every 15 seconds, one round every minute for 1 hour or one round every 3 minutes continuously. The semi-automatic loader is at the rear of the turret and can be loaded via a hatch in the turret side. The 155 mm barrel is loaded at an angle of +2° and the propellant charge is loaded into the chamber manually.

Using semi-automatic loading the turret can accommodate 23 rounds ready for use, with a further seven ready for use elsewhere in the hull. The projectiles are stowed in a linked row of tubes at the rear of the turret ready for use. The firing percussion mechanism is actuated by an electrohydraulic valve. Firing is by a push-button and using this system an initial burst rate of three rounds in 20 seconds can be achieved. The barrel elevating and balancing mechanism consists of a hydraulically actuated cylinder linked to the cradle and pivoting on the turret structure. The limits of elevation are from -4 to +70°.

There are two modes of operation for the mechanism, hand and power. Using the hand mode the barrel can be moved using a wheel to operate a hand pump linked to the elevation cylinder. In the power mode, with the hydraulic power on, the gunlayer can lay the weapon directly, using a control handle. After firing, the barrel is returned to the loading position of +2° automatically. Traversing is by a hydraulically operated and controlled gearbox; traverse is a full 360°.

The recoil system consists of two buffers and one recuperator. Firing charge 8 at an elevation of +70° the recoil force is approximately 45,000 kg.

It can also fire other types of ammunition including that used by the towed FH-70 and BAE Systems Bofors FH-77B, as well as US 155 mm ammunition types including the M107, M549A1 and M483A1.

The Palmaria has three sighting systems installed: a P170 direct firing periscope, a P186 panoramic sight for indirect sighting and a dial sight.

The P170 can be used for both observation and sighting and in the latter mode has a magnification of ×8. The optical unit of the sighting system can be replaced by a light intensification system that transforms the day periscope into a low-light device.

The P186 panoramic sight is used for indirect firing and is provided with an illuminated reticle for day or low-light level use. The reticle is fixed and pre-aligned with the optical axis.

The Palmaria can also be provided with an electronic plane converter for rapid and accurate aiming both in direct and indirect fire.

The primary fire-control system of the Palmaria is the P186 telescope that is mounted on a telescope mount. This is used for laying the weapon in azimuth and for indirect fire control. The sight has a magnification of ×4 with a 10° field of view and weighs 8 kg. Internal communications are via the normal intercommunication system and an extra external telephone point can be provided. The turret has adequate space for normal radio installations.

Oto Melara has proposed that the chassis of the Palmaria should be used for other applications, for example fitted with a similar turret to the OTOMATIC 76 mm self-propelled anti-aircraft gun system. Development of the OTOMATIC SPAAG has been completed but as of early 2008 no production orders had been placed.