Objectives: The aim of the present study was to examine the influence of self-regulation and habit on fruit and vegetable intake and physical activity, among pregnant women who intended to adhere to fruit and vegetable and/or physical activity guidelines. Design: The present study adopted a prospective study design in which data was obtained at two time points, one month apart. Methods: One hundred and seventy-nine pregnant women aged between 19 and 45 participated in this study (M = 31.09, SD = 4.05). Women completed an online questionnaire at time one which assessed demographic information, fruit and vegetable intake, engagement in physical activity, intention, self-regulation and habit. One month later they completed a time two questionnaire that reassessed intention, dietary intake, and physical activity engagement. Women who completed both time points and were classified as intenders for fruit and vegetable consumption (n=88) and for physical activity (n=19) were retained for analysis. Results: A series of logistic regression analyses revealed habit to be a significant predictor of profile membership for fruit and vegetable consumption but not for physical activity. Contrary to initial expectations, self-regulation was not able to significantly predict adherence to fruit and vegetable or physical activity guidelines. Conclusions: For pregnant women, habit strength is likely to be influential in determining adherence to the recommended fruit and vegetable guidelines. Therefore, implementing habit-formation and automaticity-based interventions could promote optimal health behaviours and outcomes, which benefit both the mother and child. To improve the generalizability of these findings, physical activity should be explored further to better understand the determinants that influence adherence to the recommended physical activity guidelines.