We examined whether individual and relationship characteristics predicted condom use in Greek young adults’ ongoing relationships. Participants were 277 university students with ongoing dating relationships who provided their demographics and information on their sexual profiles, partners, and relationships. Participants rated their relationships in terms of matrimonial and hedonistic (passionate) characteristics, and indicated whether they had used a condomat first intercourse, at latest intercourse, and consistently during the relationship. Condoms were more likely to be used at first intercourse, at latest intercourse and during the relationship when they had been used at sexual debut (first-time-in-life sexual intercourse). However, they were less likely to be used at latest intercourse, the longer and the more hedonistic the relationship. In addition, increased frequency of coital sex during the relationship was associated with less consistent condom use. It appears that condom use at sexual debut establishes a resilient habit of condom use in future relationships. However, relationship duration, sexual passion, and frequency of coital sex appear to undermine condom use. Condom use promotion should address young audiences at an early age, emphasizing that relationship length, frequency of coital sex, and passion may work against protective behavior in a relationship.