Four studies used experimental and correlational methods to investigate the effect of a "partner-achievement goal," or a personal goal for a relationship partner's successful achievement. This goal led support providers to offer unhelpful support about how to play a computer game (Study 1). It also predicted poor achievement for dieting support recipients (Study 2). The effects of partner-achievement goals were moderated by recipient expectations of success and mediated by recipient effort. Recipients with low expectations of their own success requested that their provider partners with partner-achievement goals refrain from offering them support (Study 3); they also invested less time studying Latin grammar and learned fewer Latin words over one week (Study 4). Together, these findings highlight the unique behavioral consequences of partner-achievement goals for both members of a relationship.