With a longitudinal prospective design, we examined the impact of floods on the mental and physical health of older adults and explored risk and protective factors. Method: Two hundred and seventy four older adults (age =60) completed surveys before and after a flood event. Both the surveys included measures of anxiety, depression, self-reported health, and satisfaction with life; the post-flood survey also included questionnaires on flood experience, symptoms of post-traumatic stress disorder (PTSD), stoicism, and psychological coping with floods. Results: Compared to those not personally affected (78.8 ), personally affected individuals (21.2 ) reported significantly higher PTSD symptoms, with about one in six reporting PTSD symptoms that might require clinical attention. Personally affected individuals also reported a greater increase in anxiety post-flood, but changes in their depressive symptoms and self-reported health were not significantly different from those not personally affected. Greater flood exposure and the lack of social support were the risk factors for poorer mental and physical health. Higher stoicism was associated with higher post-flood depression and poorer self-reported mental health. The use of maladaptive coping, such as venting and distraction, was associated with greater deterioration in mental health after floods, whilst emotion-focused coping such as acceptance, positive reframing, and humour, was protective against such deterioration. Conclusion: Floods had adverse psychological impacts on some older adults who were personally affected. Despite the evidence of resilience, a small proportion of older adults experienced significant difficulties after the floods. The findings in this study help understand older adults psychological responses to disasters and have practical implications for service planning and delivery.