The present study investigates the long-term post-trauma psychological reactions to Cyclone Bola, which struck the East Coast of the North Island of New Zealand in March, 1988. This study evaluates psychological morbidity in respondents, in particular it estimates prevalence of post-traumatic stress disorder (PTSD). The current study identifies factors which could influence the development of PTSD or other psychological problems which may result from a natural disaster. A questionnaire was posted to subjects identified as either having been evacuated from their homes during Cyclone Bola, or who applied for financial aid following the disaster. Four hundred and ninety three questionnaires were sent to the Gisborne area in July. 1993. One hundred and eighteen replies were suitable tor analysis. The study found that, at the time of measurement, 11.8% of respondents could be classified as PTSD cases and 17% scored in the high psychological distress group. Results did not support a direct link between the amount of adversity suffered and the psychological morbidity reported. However, there was an indirect link between the adversity suffered, the emotional distress reported by respondents at the time of the disaster and levels of psychological morbidity. Furthermore, there was support for the mediating influence of how satisfied respondents were with the help they received from relief agencies and with the social support they received at the time of the disaster. There was no support for gender differences in reactions to natural disasters. Some of these findings support previous research. Implications of these findings for future post-disaster psychological intervention are discussed.