This study examines the role of immediate social companions in the prosocial behaviors of children from two cultural communities from the USA and the Philippines. Materials for this study comprised behavioral observations drawn from the Six Cultures Study--with 612 five-minute observations of 23 children (12 girls, 11 boys) from Orchard Town, MA and 570 observations of 24 children (12 girls, 12 boys) from Tarong, Philippines, ranging in age from 3 to 11 years. Data were coded for instances of prosocial behaviors, as well as characteristics of social companions (age and relationship to actor). Results revealed several interesting findings. First, frequency of children's behaviors varied as a function of the age of their social companions. Children generally directed the highest number of prosocial behaviors towards infants and toddlers, except for younger children's prosocial behaviors towards relatives which were directed mostly towards adults. Second, frequency of prosocial behaviors varied as a function of kinship, but differently for the community groups. Tarong children were generally more prosocial towards relatives, while Orchard Town children showed more prosocial behaviors towards non-relatives. Results highlight the role of immediate contexts in prosocial behaviors of children, and the value of using cross-cultural methodology to examine contextual factors in developmental processes. (Contains 1 table and 4 figures.)