The AA artillery was subordinated to the AA Defence Command and, on 22 June 1941, it consisted of 6 regiments.
An AAA regiment was made up of 3 groups (battalions), equipped with 6 heavy batteries (75 mm Vickers/Resita or 76.2 mm Skoda), 5-8 light batteries (37 mm Rheinmetall, 40 mm Bofors, 25 mm Hotchkiss or 20 mm Oerlikon), 2 machine-gun batteries (13.2 mm Hotchkiss) and one searchlight battery (150 mm Siemens or Nedalo).
The AA artillery units were collaborating with the Watch and Air Alarm Service. This was a regiment which had 3 battalions, each with 3 sections of 9-12 watch posts. There was also the Balloon Flotilla, which consisted of 3 battalions, each with 10 companies.
From the first weeks of war AA artillery units were assigned to the Combat Air Grouping and to the 3rd and 4th Army. By the end of 1941 they succeeded in shooting down 115 enemy aircraft. Between June and July 1941, Ploesti, Bucharest, the Constanta harbour and the bridges over the Danube were main targets of the Soviet air offensive. They were often carried out by slow and unescorted DB-3 and SB bombers, which were easy targets for the Romanian AA artillery and fighters.
In the second half of 1942, the Combat Air Grouping was supported on the eastern front by the 4th AA Brigade (4th and 5th Regiments). After the encirclement of the German 9th Flak Division at Stalingrad it was the only Axis AA defence unit in the area. In some cases the soldiers of the 4th AA Regiment had to engage the Soviet tanks with the 75 mm Vickers/Resita guns.
In the summer of 1943 the AA artillery was reorganized. There were 8 regiments (1st-7th and 9th), made up of 66 heavy batteries, 55 light batteries, 14 batteries and 3 machine-gun sections, 10 searchlight batteries and 3 balloon battalions (82 balloons in total). A major part of these forces was massed in the Ploesti-Campina area. In July was created the 8th AA Regiment, which had the mission to guard Dobrogea and the Constanta harbour area in particular.
The number of units supporting the front troops was reduced and the AA defence had at its disposal 56 sections (224 guns). Later another 52 were made available for it. Also the 15th AA Regiment was created.
In the first part of 1944, the USAAF and RAF started their massive air offensive against Romania. To improve the effect of the AA artillery in low-visibility conditions Nedalo, BBT and Elascop listening devices and the Bungescu central command point, which made possible the concentration of a massive fire power, were introduced
The AA artillery units were located in the following areas:
- 3rd AA Brigade (1st and 3rd AA Regiments and a battalion from the 9th AA Regiment) - Bucharest
- 4th AA Brigade (7th and 9th AA Regiments) - Ploesti
- 2nd AA Brigade (2nd, 6th and 15th AA Regiments) - the front in Moldavia
- 1st AA Brigade (4th and 5th AA Regiments) - on the border with Hungary
- 8th AA Regiment - Constanta harbor and bridges over the Danube
Of all these units, the 4th AA Brigade by far the best equipped (had 88 mm Krupp guns) and manned. Together with the German 5th Flak Division it made up the forces around one of the best defended targets in Europe (after Berlin and the Ruhr).
After 23 August 1944, the 3rd and 4th AA Brigade remained in their designated areas. In the campaign in Transylvania the 1st AA Brigade (4th and 8th AA Regiments) supported the 4th Army, the 2nd AA Brigade (2nd and 5th AA Regiments) the 1st Army and the 6th AA Regiment the Air Corps.
On 28 December 1944 the 1st AA Division was created from the elements on the front line. It totalled 31 heavy, 27 medium, 16 light, 2 machine-gun and 2 searchlight batteries. The equipment was excellent. Most of it was captured from the German 5th Flak Division around Ploesti.
The Romanian AA gunners finished the war with 1,110 kills to their credit: Soviet, American, British and German aircraft.