Fifteen field variety trials of cassava (Manihot esculenta Crantz), were carried out in different localities of the São Paulo State, Brazil. These trials comprised of four series of 12, 12, 10 and 9 varieties each. Plants are harvested with two vegetative cycles (18-24 month old). A randomized complete-block design with four replications was used and individual and combined analyses of variance were made. The results showed that, on an average, only the IAC 12-829 variety with 39.0 t/ha yielded more than the standard cassava variety Branca-de-Santa-Catarina (25.4 t/ha).