The effects of 0, 40, 80 and 120kglha, applied as Triple superphosphate, on seed yields and quality of five peanuts genotypes were studied. Three cultivars (Tatu, Oirã and Tupã) and 2 lines (FCA 170 and FCA 265) were grown in field conditions in Botucatu, São Paulo, Brazil, in the spring of 1991. There were not observed significant effects of phosphoru in the seed physiological quality, but there was an increase in seed yields up to 80kg/ha of P2O5/ha. Tatu, FCA 170 and FCA 265 showed higher seed quality when compared with Oirã and Tupã. These was no significant difference in seed yields among the genotypes.