Diabetic ulcers are one of the complications that often occur in patients with DM. The aim is to develop a behaviour model for diabetic ulcer prevention by integrating Lawrance Green Theory and the Theory of Planned Behaviour. An explanative observational design was used with a cross-sectional approach. The population consisted of DM patients who had underwent treatment at the internal medicine clinic of Sidoarjo District Hospital. The sample size of 133 respondents was obtained through purposive sampling. The data analysis used Partial Least Square. Predisposing factors (knowledge), supporting factors (availability of health facilities and accessibility of health resources) and driving factors (the role of health workers and family support) significantly influence the main factors (attitudes toward behaviour, subjective norms and perceptions of self-control) with a statistical T value>1.96. The main factor influences intention (T = 48.650) and intention influences behaviour (T = 4.891). Intention is influenced by the attitudes toward behaviour, subjective norms and self-control perceptions. Good intentions can increase the preventive behaviour related to diabetic ulcers. Increasing the diabetic ulcer prevention behaviour can be done by providing regular education to both the patients and their families about diabetic ulcers and their prevention through the appropriate management of DM, lifestyle modification and regular foot care that requires active involvement from the family and health care workers.