Boris Kotliarskii was born in 1914 in the village of Nestashka, Kiev Province, Ukraine. After completing seven years of school, Boris worked as an electrician at the Leningrad train-repairing factory. In 1935 Kotliarskii joined the Red Army and in 1938 graduated from the Artillery School in Kiev. In September 1939, following the Molotov-Ribbentrop Pact, he participated in the Soviet annexation of western Ukraine.
After the outbreak of the German-Soviet war on June 22, 1941, Boris Kotliarskii served in different posts. In 1944 the artillery regiment under Kotliarskii's command was involved in the fighting for the city of Kowel (March-April 1944), launching a massive attack against the German defense that enabled Red Army troops to capture the city. On July 29, 1944 Colonel Kotliarskii's artillerymen were assigned to capture and hold a bridgehead on the left bank of the Vistula River, near the city of Puławy, Poland. Under cover of darkness Kotliarskii's artillery unit successfully crossed to the left bank of the Vistula River and, assisted by several other artillery regiments, for several days repelled German counter-attacks. The bridgehead was held and fortified so that the main Red Army troops were able to cross the Vistula. In January 1945, during the Vistula–Oder Soviet offensive operation (12 January - 2 February 1945) the artillery regiment under the command of Kotliarskii assisted the troops of an infantry regiment to break through the German lines and eventually capture the city of Radom. On February 27, 1945 Colonel Boris Kotliarskii was awarded the title of Hero of the Soviet Union for his contribution to the Red Army's crossing of the Bug, Vistula, and Oder Rivers.
During the war Colonel Kotliarskii was also awarded the Order of Bodgan Chmielnitsky, 2nd class, and the Order of Suvorov, 2nd class, which were given only to commanders of the Red Army. Boris Kotliarskii ended the war in Berlin.
After the war, in 1946, Kotliarskii graduated from the High Artillery School for Officers and in 1952 - from the prestigious Frunze Military Academy in Moscow.
In 1960 Boris Kotliarskii retired from the Soviet Army and settled in Kiev, where he died in 1993.