|Pan American Games|
|1975 Mexico City||Team|
|1979 San Juan||Team|
Early international career
Leite, a 6'10 center from Rio de Janeiro, first suited up for Brazil at the age of 18 in the 1970 FIBA World Championship. "Marquinhos" played sparingly, scoring 6 points in 4 appearances as Brazil took the silver medal. Leite remained with the Brazilian national basketball team and was one of the team's top players as they won the gold in the 1971 Pan American games a year later. In 1972, Leite caught the eye of American college coaches as he averaged 16 points per game in the 1972 Summer Olympics in Munich.
Leite's Olympic performance caught the eye of Pepperdine University coach Gary Colson. Colson recruited him to the California school, where he starred from 1973 to 1976. Leite made an immediate impact in the West Coast Athletic Conference, earning second team All-WCAC honors as a freshman and first team honors as a sophomore.
As a junior in the 1975–76 season, Leite and junior college transfer Dennis Johnson led the Waves to a conference title and the school's second division I NCAA tournament appearance and first NCAA tournament win. The Waves beat Memphis State in the first round before losing to defending champion UCLA in the Sweet 16. Leite was named the WCAC player of the year and an honorable mention All-American. Following the season, Marcos Leite informed Colson that he would forgo his final year of college eligibility to play professionally.
For his college career, Leite scored 1,119 points (18.7 points per game) and grabbed 638 rebounds (10.6 per game).
Professional and later international career
While at Pepperdine, Leite continued to represent his country as a member of Brazil's national team in the 1974 FIBA World Championship and the 1975 Pan American Games. In later years, he was also a part of Brazil's 1978 and 1982 World Championship squads and their 1980 and 1984 Olympic teams.
Professionally, Leite played in his native Brazil (for Fluminense, Flamengo, EC Bredesco and E.C. Sírio) and in Italy (Synudine Bologna and Athletic Genova). While he was drafted by the Portland Trail Blazers in the 1976 NBA Draft (10th round, 162nd pick), he never played in the NBA. He retired in 1989.