Social support is an important variable in occupational stress research and theory, yet little is know about the factors that influence the amount of social support one gives, and receives at work. We examined personality (extraversion, neuroticism, and agreeableness) and reciprocity as potential antecedents to giving and receiving support from co-workers. Data collected from 108 participants employed in a number of organizations indicated that giving social support was positively associated with the receipt of social support. Both extraversion and agreeableness predicted giving and receiving non-job support and positive work-related support. The relationship between personality and social support received was, in many cases, mediated by social support given.