Guaita played for Estudiantes de La Plata, where he was part of the famous attack "Los Profesores". In 1934, he moved to Italy, where he probably played his best football. He played two seasons for A.S. Roma from 1933 to 1935. He was the top-scorer of the League in 1934–35, with 28 goals. He became known as "Il Corsaro Nero". Fearing being drafted by the Italian army, in 1936, he returned to Argentina, where he played for Racing Club de Avellaneda and, again, Estudiantes de La Plata. He retired at the end of the 1939 season.