This study explored reciprocity in the relationships of men caregivers of cognitively impaired older adults. Reciprocity is a dimension of social support that is important in caregivers' ability to sustain supportive relationships. Equity theory predicts that inequitable (non-reciprocal) exchanges will result in termination of relationships. The objective of the study was to identify the context in which reciprocity was present or absent, the characteristics of reciprocity in caregivers' relationships with the care recipient, family and friends, and the men's feelings about reciprocal social support during caregiving. Twenty-two men caregivers were interviewed three times over 18 months. Study findings were confirmed in a focus group discussion with seven caregivers. Three variations in reciprocity in the men's relationship with the care recipient were identified: waived reciprocity, generalized reciprocity and constructed reciprocity. Those experiencing constructed or generalized reciprocity described positive feelings, whereas men identifying waived reciprocity described either positive or negative feelings. When reciprocity was absent the men described giving care on the basis of obligation with either mixed or negative feelings. Reciprocity in relationships with friends and family is also described. The study findings support the assumptions of equity theory about reciprocity; however, perceptions of obligation may be better understood in the context of the principles of justice and caring.