We propose that the primary attachment process that influences partner choice is a normative one, the desire to form a secure attachment bond, and that a potential partner's attractiveness is, in part, a function of the degree to which the partner can offer the opportunity to form a secure attachment bond. An experimental test of the attachment-security hypothesis was conducted with male and female (N= 282) heterosexual college students in the southeastern United States who had previously been classified as having one of four attachment styles: secure, preoccupied, fearful, or dismissive. Participants read scenarios (derived from Pietromonaco & Carnelley, 1994) that depicted a relationship with an opposite-sex partner who displayed one of the four attachment styles, rated their reactions to the relationship, and assessed the imaginary partner on 20 personality traits. Results provided support for the attachment-security hypothesis in two ways: (a) secure partners elicited more positive and less negative emotions than all other partners, followed by preoccupied partners, who elicited more positive emotions than either avoidant type, and (b) for the explicit choice of romantic partners, secure partners were preferred to all insecure types, who did not differ from each other. Both preoccupied and dismissive participants saw partners similar to themselves as more secure than did the other participants.