The effect of large and small favors on gratitude was tested using a behavioral measure. Participants were 149 undergraduates (120 female 29 male). Half received raffle tickets for a US$100 prize and half received tickets for a US$10 prize. Some received tickets from another (fictitious) student and others received tickets by chance. Participants receiving a favor subsequently distributed more tickets to the other student; participants receiving a more valuable favor also distributed more (ps 5 0.05). Self-reported grateful motivation predicted distribution better than did indebtedness. Grateful motivation mediated the relationship between favor and distribution (p 5 0.05). Results provide validity for a behavioral measure of gratitude tentatively support favor value as a determinant of gratitude and further differentiate between gratitude and indebtedness.