CONTEXT: Despite declining fertility in Ghana, modern contraceptive use-even in urban areas-is low for reasons that remain unclear. Few studies have explored what drives fertility decisions and contraceptive use among contemporary urban residents within a relationship context. METHODS: In-depth contraceptive life history interviews were conducted among a purposive sample of 80 sexually active women and men living in Accra. RESULTS: Contraception is viewed favorably, although the timing and choice of method strongly depends on the type and stage of relationship. At sexual debut and at first sex with a new partner, sex is usually unprotected. Many women show agency in subsequently negotiating condom use; men also show motivation to practice contraception. As relationships stabilize, couples abandon condoms and adopt traditional methods, out of fear that modern methods could affect fertility. After a first birth, couples prefer modern contraceptives to space children, but side effects often lead women to switch methods or discontinue use; women in supportive relationships are more likely than those in unsupportive relationships to continue use of modern contraceptives despite side effects. After reproductive goals have been realized, couples revert to using traditional methods to avoid further exposure to "chemicals." CONCLUSIONS: Contraceptive programs may be more successful if they target messages according to stage of relationship, involve men and work with people's desires to use traditional methods at certain times to ensure that they can do so safely.