Up to and including World War: The Madsen was considered expensive to produce, but was known for its reliability. Thirty-four countries bought the gun, in a dozen different calibres, before and after World War I.
The Imperial Russian Army bought 1,250 Madsens for the cavalry and deployed them during the Russo-Japanese War. The Imperial Russian Air Service used Madsens to equip their Morane-Saulnier G and Morane-Saulnier L monoplanes, mounting the gun to fire over the propeller. The German Army deployed the Madsen in 7.92 mm calibre in 1914, arming infantry companies, mountain troops and later storm troopers.
Inter-war era: Among the fighting forces with the Madsen in their arsenals in the immediate aftermath of World War I were the Czechoslovak Legions in Russia, fighting the Bolsheviks in Siberia. The Madsen also saw service in China during the Warlord era.
World War II: Madsen machine guns were still in use in April–June 1940 as the Norwegian Army's standard light machine gun in the Norwegian Campaign, 3,500 M/22s in 6.5×55 Krag being available for the defence of Norway. By 1940 each Norwegian infantry squad had one Madsen machine gun, the Norwegians having previously grouped their Madsens in separate machine gun squads.
Post-war: Ireland had a total of 24 Madsen machine guns, all in .303 calibre. They armed the Irish army's Landsverk L60 light tanks, Leyland Armoured Cars, Landsverk L180 armoured cars, and Dodge Armoured Cars. In the 1950s .30 Browning machine guns replaced the Madsens still in Irish service.
Portuguese Colonial War: The Portuguese Army used Madsen machine guns during the Portuguese Colonial War of the 1960s and 1970s. Madsens served as temporary armament for Auto-Metralhadora-Daimler 4 × 4 Mod.F/64 armoured cars, which were Daimler Dingos modified with the addition of a turret-like structure.