<p>The present study explores the mental and sexual health of multisexual individuals in Greece, a topic largely underexplored in international literature. Using a sample of 2798 Greek adults, we compared multisexual and heterosexual individuals on well-being and psychosexual aspects, employing the Multidimensional Sexuality Questionnaire and the Mental Health Continuum – Short Form. Additionally, we examined the impact of participants’ partners’ sexual orientation on a range of psychosexual aspects. Consistent with the existing literature, findings indicated that multisexual individuals reported lower well-being and greater psychosexual difficulties than heterosexuals. In addition, gender differences emerged, with multisexual men exhibiting higher social well-being and positive functioning than multisexual women, possibly due to greater societal privilege in Greece. However, despite this, multisexual men also experienced greater psychosexual difficulties. Moreover, partners’ sexual orientation affected only multisexual men, influencing their social well-being and sexual depression. The absence of this effect in multisexual women may be attributed to their greater adaptability and the superficial validation of female multisexuality by societal norms. Furthermore, sexual satisfaction and sexual depression consistently mediated the relationship between sexual orientation and well-being, underscoring their role in explaining lower well-being levels among multisexual individuals. Findings should be interpreted within this sociocultural context. Practical interventions, limitations, and future research directions are discussed.</p>