There has been limited research on the experiences of men who have sex with men and transgender women in Timor-Leste. Previous research has suggested a phenomenon by which same-sex-attracted men and transgender women have sexual and intimate relationships with straight-identifying men or mane-forte. Transactional sex has also been reported to be common. This paper, which complements a larger national size estimation among key populations at risk of HIV, further investigates sexual and social identities and roles, including sexual practices, among men who have sex with men and transgender women in Timor-Leste. Fifteen interviews were conducted with a profile of participants from urban and rural settings. Using inductive thematic analysis, we found that gender identity played a significant role in sexual relationships, with mane-forte having power over their sexual partner(s). Transactional sex was also found to be customary. Some participants experienced stigma, discrimination, sexual coercion and violence, while others, such as mane-forte, did not. Our research suggests that gender identity and power are significant in sexual relationships between men who have sex with men and transgender women in Timor-Leste, have implications for HIV prevention efforts and may reflect gender norms within the broader community.