The genus Pereskia is an exception in the family Cactaceae in that it bears typical and perennial leaves. Pereskia is widely distributed from North of Mexico to South of Brazil. At the Santa Genebra Reserve (22°44'45'S, 47°06'33'w), Campinas, Southeast Brazil, all individuals of P. aculeata found were tagged. About 100 fruits were collected in paper bags and transferred to the laboratory where they were weighed and measured. Diurnal and nocturnal observations were made from 1992 to 1994 to determine the frugivores. Germination tests were made with seeds from monkey faeces and intact fruits. Fruiting occurred from May to October. The fruit is an orange fresh berry and the pericarp shows circles with leaves and thorns which fall at maturity. The weight is 2.03 g ± 0.92 and diameter 1.50 cm ± 0.23 (n = 96). The results on frugivory are based on 88 feeding records. The most common animals observed feeding on ripe fruits were the capuchin monkey (Cebus apella) and the brown howler monkey (Alouatta fusca), accounting for 47,7% and 39,8% of records respectively. Some birds species were observed pecking on the pulp of mature fruits. Nocturnal animals were not observed feeding on P. aculeata. The seeds were not affected by light intensity; 75% germinated at both light and darkness conditions (n = 100). Seeds from faeces of the monkeys germinated better than the others from untouched fruits: 100% from faeces of the brown howler monkey (n = 50) and 90% from the capuchin monkey (n = 50). Our results indicate that monkeys are the main seed dispersers of P. aculeata at the Santa Genebra Reserve.573479486