Lazar Nikolov was born on August 26, 1922 in Burgas. He began to show interest in music as a child. He was influenced by his father and brother, who are active in music but are not professional musicians. As a child, Nikolov tried to play the piano and violin. At school he took an active part in school concerts. He made his first attempts to compose around the age of 16. In 1946 he graduated from the State Academy of Music with piano in the class of Professor Dimitar Nenov. A year later he graduated from the same school with composition under Professor Pancho Vladigerov. Among his teachers at the academy were also Parashkev Hadjiev and Veselin Stoyanov.
Nikolov's work is large and diverse. It includes two operas, six symphonies, works for chamber, symphony and string orchestra, choral songs, sonatas for various instruments. Nikolov creates music for theatre productions and dozens of Bulgarian feature and documentary films. His works have been performed in European countries, Brazil, Canada, USA and others. He participated in music festivals, including the Warsaw Autumn (1962, 1964 and 1968), the Zagreb Biennale (1967) and Witten (1998). He is the author of the book "My World" (1998), which includes thoughts, conversations and interviews with the composer.
In addition to composing, Nikolov performs pedagogical activities. He has been teaching at the State Academy of Music since 1961, where he retired as a professor of score reading.
He was twice nominated for a member of the Bulgarian Academy of Sciences. The first time his place was taken by another candidate, and the second time Nikolov refused to accept the academic title due to fatigue. He was a member of the Union of Bulgarian Composers and its chairman from 1992 to 1999.
He has twice been awarded the title of "Doctor Honoris Causa", respectively by the Academy of Music, Dance and Fine Arts (1997, for overall composition) and the State Academy of Music "Pancho Vladigerov" (2002). He is a holder of the Stara Planina Order (1997).