To determine if an interactive, computerized Video Doctor counseling tool improves self-reported diet and exercise in pregnant women.A randomized trial comparing a Video Doctor intervention to usual care in ethnically diverse, low-income, English-speaking pregnant women was conducted. Brief messages about diet, exercise, and weight gain were delivered by an actor-portrayed Video Doctor twice during pregnancy.In the Video Doctor group (n=158), there were statistically significant increases from baseline in exercise (+28 min), intake of fruits and vegetables, whole grains, fish, avocado and nuts, and significant decreases in intake of sugary foods, refined grains, high fat meats, fried foods, solid fats, and fast food. In contrast, there were no changes from baseline for any of these outcomes in the usual care group (n=163). Nutrition knowledge improved significantly over time in both groups but more so in the Video Doctor group. Clinician-patient discussions about these topics occurred significantly more frequently in the Video Doctor group. There was no difference in weight gain between groups.A brief Video Doctor intervention can improve exercise and dietary behaviors in pregnant women.The Video Doctor can be integrated into prenatal care to assist clinicians with effective diet and exercise counseling.