Poor pregnant women can benefit from interventions that include nutrition education and medical care services that may prevent malnutrition, food insecurity, and promote positive pregnancy outcome. Food insecurity is asymptomatic measure of malnutrition. In Nigeria, malnutrition is one of the contributing factors to maternal and infant mortality. However, studies on the effect of free pre and postnatal medical care services and nutrition intervention in rural communities is limited. The aim of this study was to determine the effect of free medical care services and nutrition education on food insecurity and dietary protein intake of poor pregnant women participating in a community-based intervention program. Four hundred and ninety-nine pregnant women were recruited after they had enrolled in a community-based prenatal intervention program. The participants gave oral consent to be in the study. Participants responded to food frequency questionnaire and food security questions before and after the intervention program. Data were statistically analyzed using SPSS computer software. Pearson Chi-square was used to evaluate the differences between food insecurity levels and dietary protein and carbohydrate intake. Results show that food insecurity reduced significantly after the intervention program. The participants with high school education food security increased significantly more than those with less than high school education at p< 0.05. In addition, food insecurity was associated with low dietary protein intake, but improved after the intervention p< 0.05.