Introduction: Excessive gestational weight gain (EGWG) can be prevented by a structured nutrition and exercise behaviour change program implemented during pregnancy, however research is inconsistent on the efficacy of these programs in the obese (body mass index; BMI≥30.0kg·m2) pregnant population. The purpose of this study was to determine if there was an increase in adherence to nutrition and exercise goals from obese pregnant women if a family based component was added to the intervention. Methods: Retrospectively, obese pregnant women who participated in the (NELIP; a nutrition and exercise program designed to prevent EGWG, n=38) and the Family-based Behavioural Treatment (FBBT) plus NELIP (FBBT+NELIP; n=29) were scored on meeting the goals of the program (3 exercise and 3 nutrition) for a maximum adherence score of 6. Weight gain on the program was assessed as gained appropriately or excessively according to the Institution of Medicine (2009) guidelines. Adherence scores were compared between women who gained excessively or appropriately within and across programs. Results: Within programs women who gained appropriately had significantly greater overall adherence than women who gained excessively (p<0.05). There was no difference in total adherence between women who gained appropriately on NELIP (n=21; 80% total adherence) or FBBT+NELIP (n=15; 73% total adherence), however exercise only adherence was greater for NELIP (93%) than FBBT+NELIP (70%; p<0.05). Conclusion: Increasing adherence to nutrition and exercise behaviour change programs during pregnancy can prevent EGWG in women with a pre-pregnancy BMI of obese. Benefits on adherence from adding a family based component needs further exploration.