This study attempts to demonstrate factors governing reciprocity of helping behavior in nursery school children. A time sampling method with a pre-set 10 category system was used to record the psychological and task helping behavior of 19 preschool children (mean age 5 1/2 years) over a 2-month period. Each child also completed a sociometric status test and was rated on his relative helpfulness by two teachers. It was found that help given by children was reliably reciprocated by peers. Reciprocity was stronger when the recipient was liked by the giver than when the recipient was disliked. High sociometric status children received more help than they gave while low sociometric status children gave more help than they received. A negative relationship was found between sociometric status and both psychological and directed (solicited) help received. Helping behavior occurred primarily between same sex peers and consistent sex differences were found in favor of males on all observational measures of helping behavior. (Author/SB)