Purpose This study draws from social comparison theory to explore why and under which circumstances individuals receiving idiosyncratic deals (i-deals) are likely to help their co-workers. Design Data were collected with an alumni association of engineers. Participants completed two questionnaires (N = 182 at Time 2). Findings We find that the relationship between i-deals and helping behavior is not direct, but is mediated by organizational-based self-esteem. This relationship is stronger when i-deal recipients believe that their co-workers do not have the opportunity to get i-deals for themselves. Implications I-deal recipients are expected to help their colleagues because helping colleagues is consistent with the positive self developed thanks to i-deals. When co-workers have the opportunity to get i-deals for themselves, social comparison between the i-deal recipient and colleagues is likely to be more salient, which strengthen the indirect relationship between i-deal and helping behavior. Originality This study tests i-deals from the vantage point of social comparison theory rather than from the perspective of social exchange. We thereby provide a richer account of the complexities involved in helping behavior. By exploring contextual variables that are likely to trigger social comparisons, we also expect to better understand the circumstances under which i-deals are likely to be associated with helping behavior.