AIMS: Personal models of diabetes comprise beliefs about symptoms, treatment effectiveness, consequences and emotional responses to possible future complications. They are associated with, and influence, self-care behaviour. Little work has examined potential influences on the development and maintenance of personal models. The aims of this study were: (i) to assess changes in personal models over 2 years from diagnosis of diabetes; and (ii) to examine the relative contributions of health threat communication (at diagnosis, since diagnosis, during follow-up care) and personality to personal models of diabetes 2 years post-diagnosis. METHODS: Newly diagnosed patients were interviewed at diagnosis (< 3 months; time 1) and 6 months (time 2), 1 year (time 3) and 2 years (time 4) after diagnosis. Data were available for 158 patients at time 1 (32 Type 1 patients and 126 Type 2 patients), 147 at time 2, 142 at time 3 and 138 at time 4. RESULTS: Perceptions of symptoms, consequences, course and control of diabetes remained stable over time. Emotional responses decreased and illness coherence (perceived understanding) increased over time. Health threat communication was a stronger predictor of personal models than personality. Emotional responses to diabetes 2 years after diagnosis were predicted by perceptions of a threatening health message (at diagnosis 18%, at follow-up 5%). Health threat communication predicted perceptions of serious consequences (at diagnosis 5%, at follow-up 9%). Perceptions of a reassuring message during follow-up were related to beliefs of treatment effectiveness (26%). CONCLUSIONS: The communication of information and the way it is perceived is an important determinant of the patient's view of their diabetes. The initial effects of the education process at diagnosis persisted 2 years after diagnosis.