Justo Galaviz competed at the 1976 Montreal Olympic Games and three times at the Central American and Caribbean Games (1978, 1982, 1986). At the CAC Games he won two silver (1978 team time trial, 1986 individual pursuit) and two bronze medals (1982 team time trial, 1986 team pursuit). Galaviz also won a bronze medal in the team time trial at the 1983 Pan American Games. He was national champion several times in the individual pursuit and team pursuit, and in 1986 set the Venezuelan record for the hour ride on a track. Galaviz won 21 stages in the Tour of Venezuela. His two major wins were at the 1980 Vuelta a la Independencia Nacional in the Dominican Republic and the 1983 Vuelta Ciclista Aragua.