[1] The division advanced from Mogilev through Pogost, Cherven, Smilovichi, Dzerzhinsk, Novogrudok, Novoelnyu, Pruzhany, Ruzhany, Slonim, Kamenets, Vysokoye, Bielsk Podlaski, and Hajnówka.

[4] This plan was modified and in the final version received by district commander Colonel General Dmitry Pavlov on 9 June in a directive of the People's Commissar of Defense, the 121st was instead assigned to the 24th Rifle Corps in the second echelon of the 3rd Army, which was deployed along the line of Vidzy, Sventyany and the Viliya River.

This resulted in new orders that directed the division to take up its starting positions by 20:00 on 14 June in the area of Gervyaly, with flanks at Pupina and Borovka 8 to 15 kilometers northwest of Vidzy.

When the invasion began on 15 June, the 121st approached the state border at 16:00 and by the end of the day reached Gyajunai, south of Lake Dysnykštis.

[8] That day, the Lithuanian government found resistance impossible and accepted the Soviet ultimatum to Lithuania, under which the 4th Rifle Corps was planned to be stationed in the Panemunis area.

[13] It is listed as being part of the 47th Rifle Corps, directly subordinate to the Western Special Military District, on the eve of Operation Barbarossa, the German invasion of the Soviet Union.

[14] After the beginning of Operation Barbarossa on 22 June 1941, the division as took up defensive positions on the eastern bank of the Shchara River in the Slonim area on the next day as part of the 13th Army.

From 24 June it fought in heavy defensive battles, retreating to Baranovichi, Slutsk, Osipovichi, the village of Boyarshchina, and Starye Dorogi.

The division was transferred to the 60th Army on 28 June and fought in attacks in the Battle of Voronezh and by 4 July reached the area of Zemlyansk, but was forced to retreat to the line of Medvezhye and Chistaya Polyana, covering the crossings of the Don.

For participation in the recapture of Starokonstantinov, Izyaslav, Shumsk, Yampol, and Ostropol the division was awarded the Order of the Red Banner on 19 March.

In late November Dotsenko handed over command of the 121st to division chief of staff Colonel Ivan Generalov and left to study at the Higher Military Academy.

For participating in the capture of Bohumín, Fryštát, Skoczów, Čadca, and Bytča the division was awarded the Order of Suvorov, 2nd class, on 4 June 1945.

[20] The division was disbanded at Osiek between 28 and 30 June after completing a march from Golczowice, with its troops being used to bring units of the 52nd Army up to strength by 6 July.