This study investigated attraction in heterosexual cross-sex friendships. Study I used in-depth interviews with 20 dyads (40 participants) to uncover four types of attraction that occur in cross-sex friendships -- subjective physical/sexual attraction, objective physical/sexual attraction, romantic attraction, and friendship attraction. These types of attraction are subject to being symmetrical or asymmetrical, and may incur changes over time. Study II (N=231) used a questionnaire to assess the frequency of each type of attraction and the frequency which types of attractions are perceived to change. The most prevalent form was romantic attraction. The implications of these results for understanding both cross-sex friendships and the process of attraction are discussed.