Iancu Dumitrescu began composing his mature works in the early 1970s. In 1976 he founded the Hyperion Ensemble, described as "a multimedia group dedicated to experimental music". Several of Dumitrescu's early works for solo contrabass were recorded by the noted avant-garde bassist Fernando Grillo.
Dumitrescu describes his music as "acousmatic", but disclaims a relationship with the Acousmatic music of French musique concrete pioneer Pierre Schaeffer. He accepts the "spectralist" label, though he distinguishes his work from some others in the spectral school in that it is not serial.
Iancu Dumitrescu was married to fellow composer Ana-Maria Avram (1961-2018); they have more than 20 joint releases on their Edition Modern label. Recordings of Dumitrescu's works have also been released by Edition RZ, ReR Megacorp, Generations Unlimited, and other record labels. He is represented by Editions Salabert.