Weight loss maintenance is very difficult to achieve, with most individuals' weight stabilizing only slightly below their pre-loss baseline level within five years. The present study used Relapse Prevention Model (RPM) variables coping, self-efficacy and lapsing in addition to other variables previously found to influence maintenance rates, to predict percentage of weight loss maintained (PWLM). Fifty-six females and ten males, who had lost at least 5% of their body weight, completed the Hypothetical High Risk Situations Questionnaire (HHRS), the Weight Efficacy Lifestyle Questionnaire (WEL), a Self-monitoring Seven-day Lapse Diary (LD) and the Questionnaire on Eating and Weight Patterns (QEWP). Three variables significantly predicted PWLM: perceived severity of lapses, vigilance for diet and exercise and maintenance time. The results are discussed with respect to the applicability and influence of the RPM and additional variables on weight loss maintenance. Implications for the development of new maintenance treatments, based on the RPM are also considered.