Objective: Research suggests that lesbian and gay people's disclosure of their sexual orientation to parents is associated with better mental health and identity adjustment. However, adolescents and younger adults have been the main focus with little known about the experiences of older people. The following study focused on older lesbian and gay adults, and examined whether believing that their parents knew about their sexual orientation is linked to better current mental health and identity adjustment.Method: A survey of 548 lesbian and gay adults aged 60 years and older in Australia measured psychological distress, positive mental health, internalised homonegativity, sexual identity affirmation, and whether participants believed their parents knew about their sexual orientationResults: After controlling for age of first disclosure, whether their parents were alive, and socio-demographic variables, women who reported at least one parent definitely knowing of their sexual orientation were significantly lower on psychological distress and higher on positive mental health and identity affirmation than those who reported neither parent knowing or were uncertain of their parents' knowledge. No significant effects were found for the men.Conclusion: Believing that at least one parent definitely knew about their sexual orientation was linked to better mental health outcomes among lesbian women, but not among older gay men. These findings reveal a potential risk factor for poorer mental health among older lesbian women, as well as important gender differences, and may be useful in understanding and supporting the well-being of older lesbian and gay adults.