Boris Aljinović was born on June 23, 1967, in Berlin. Initially, Aljinović planned to start a career as a comic-strip artist but instead became an actor by accident in the mid-1980s. After several smaller parts in theatre productions for the English Berlin Play Actors Group and short movies for dffb, Aljinović enrolled in English Literature and Romance studies. Three years later, he went to the famous Ernst Busch drama school and made his actor's degree in 1994.

In the same year, Aljinović became a cast member of the theatre in Cottbus. In 1995, Aljinović returned to Berlin and became a cast member of the Renaissance theatre where he delivered his now considered legendary performance of Adolf Hitler in "Noch ist Polen nicht verloren".

Still in 1995, Aljinović made his movie debut in Hal Hartley's episodic film "Flirt". Unlike many of his colleagues, Aljinović rarely had to promote his acting skills in supporting roles to get larger parts but was cast in leading roles from the beginning of his career. With his competent yet understated style of acting Aljinović starred as a leading actor in several film and TV productions such as the romantic comedy "Der Strand von Trouville" ("Trouville Beach") or the black comedy "Drei Chinesen mit dem Kontrabass" ("Three Chinamen with a Double-Bass").

Besides his film work, Aljinović still works regularly for the theatre. Another counterpoint to his mainly comedian parts is his role in the TV crime series "Tatort". Since 2001, Aljinović plays the observer Felix Stark alongside the aggressive commissar Till Ritter (Dominic Raacke). One of his most successful films was "7 Zwerge - Männer allein im Wald" ("Seven Dwarfs") by Otto Waalkes. The movie"s sequel, "7 Zwerge – der Wald ist nicht genug", sees Aljinović again in the role of the grumpy and introverted dwarf Cloudy who is a most welcome contrast to the hysteric daftness of his fellow dwarfs Martin Schneider and Otto Waalkes.

Boris Aljinović is living with the actress Antje Westermann in Berlin.