The casualties of the Second Nagorno-Karabakh War, fought between Armenia, the self-proclaimed Republic of Artsakh and Azerbaijan, officially number in the low thousands. According to official figures released by the belligerents, Armenia and Artsakh lost 3,825 troops, with 187 servicemen missing in action, while Azerbaijan lost 2,906 troops, with 6 missing in action. The Syrian Observatory for Human Rights reported the deaths of 541 Syrian fighters or mercenaries fighting for Azerbaijan. However, it is believed that the sides downplayed the number of their own casualties and exaggerated the numbers of enemy casualties and injuries.
The total number of reported civilian fatalities on both sides is at least 185, the whereabouts of 21 Armenian civilians remain unknown. Civilian areas, including major cities, have been hit, particularly Stepanakert, Martuni, Martakert, Shushi in the Republic of Artsakh and Ganja, Barda and Tartar in Azerbaijan, with many buildings and homes destroyed.
Military casualties
Armenian
The Armenian side reported the deaths of 3,825 servicemen during the war, while 187 remained missing. The Armenian losses included 742 killed servicemen of the Artsakh Defence Army and 45 missing.
By 30 September, the Azerbaijani authorities claimed more than 700 Armenian servicemen were killed or wounded. Armenian Colonel Sergey Shakaryan and Colonel Vahagn Asatryan also died. On 2 November, Artur Sargsyan, Artsakh Republic Deputee Minister of Defense, was killed in combat.
Armenian sources also reported the deaths of several sportspeople in the military: Gor Sargsyan, a member of Armenian judo youth team, Albert Dadoyan, a European powerlifting champion, Tatul Harutyunyan, the champion of Armenia in powerlifting, Erik Saryan, player of FC Lokomotiv Yerevan, and Liparit Dashtoyan, a former player of FC Alashkert-2.
Azerbaijani
During the conflict, the government of Azerbaijan did not disclose the number of its military casualties. This was the first time Azerbaijan did not provide data on combat casualties, whereas during the First Nagorno-Karabakh War in 1988–1994 and in the April 2016 clashes, the Azerbaijani army reported this information. On 8 December 2020, the Azerbaijani Defense Ministry released a full list of military casualties, with names, ranks and birth dates. By 21 October 2021, the list was updated to include the deaths of 2,906 servicemen, with another 6 missing in action.
The Armenian side reported 7,630 Azerbaijani soldiers and Syrian mercenaries were killed.
Similar to the Armenian side, Azerbaijani sources also reported the deaths of athletes serving in the military: Arif Qeybiyev, a three-time champion of Azerbaijan in cross country running, and Mukhtar Qasimli, the champion of Azerbaijan in bodybuilding. On 22 October, the National Hero of Azerbaijan and veteran of the 2016 clashes, Colonel Shukur Hamidov, was killed. On 23 November, Colonel Babak Samidli died from a land-mine in post-armistice search for missing soldiers.
On 25 October, the death of an ethnic Russian Azerbaijani soldier, Dmitry Solntsev, was reported. On 27 October, the first woman military casualty was reported, a combat medic who died while taking wounded soldiers from the battlefield.
Syrian mercenaries
In December 2020, the Syrian Observatory for Human Rights reported the deaths of 541 Syrian fighters or mercenaries fighting for Azerbaijan. The dead included a veteran commander of the Turkish-backed Hamza Division, whose death was reported by Sayf Balud. In April 2021, Syrians for Truth and Justice confirmed 293 of these deaths.
Civilian casualties
Armenian
According to Armenian sources, on 27 September, two civilians were killed by Azerbaijani shelling in Aghdam Province, with approximately a dozen injured in Stepanakert; the Azerbaijani Defense Ministry denied these claims. On 10 October, Armenian media reported the killing of two civilians in Hadrut, a mother and her son with a disability, according to Armenia the killing would have been carried out by Azerbaijani infiltrators. Armenian authorities reported 85 Armenian civilians were killed and 21 were missing in the war. However, a doctor in the city of Stepanakert reported that up to 300 to 400 Armenian civilians had been killed in the war as of 25 October.
Armenian sources also indicated the clashes have displaced approximately half of Nagorno-Karabakh's population or approximately 70,000 people.