Lamelas studied at the Academia Nacional de Bellas Artes [National Fine Arts Academy] in Buenos Aires. During the 1960s he was one of the leaders of the vanguard movement that was spawned at the Instituto Torcuato di Tella. In 1968 he traveled to London and studied at St. Martin’s School of Arts with a British Council grant. In 1978 he moved to Los Angeles; in 1988 he took up residence in New York and from 1991 to 1997 divided his time between New York and Brussels. In 1998 and 1999 he lived in Berlin, and since 1999 has been dividing his time between Los Angeles, Paris and New York.

He was the Argentinean representative at the 9th Sao Paulo Biennial (1967), where he received the Sao Paulo Biennial Award for his installation; he also represented Argentina at the 34th Venice Biennial (1968). In 1972 he took part in Documenta 5, Kassel.

Lamelas has been among the most important proponents of a conceptual approach to art. In his projects, Lamelas deals with the question of the limits of art's temporality, and its potential for creating alternative processes of communication and cognition. Recent solo exhibitions include Museum für Gegenwartskunst, Basel (2008); Wien Secession, Vienna (2006); and Museo Nacional Centro de Arte Reina Sofia, Madrid (2005). He was part of the group exhibition The Quick and the Dead at the Walker Arts Center, Minneapolis (2009).

In this 2006 interview Javier Villa talks to Lamelas about leaving Argentina, his time working abroad in his early years and his interest in objective aesthetics.