Low-income pregnant women of Mexican descent were studied to determine whether their food habits could be improved by nutrition education. Biochemical indices of nutritional status were also investigated. Twenty-four-hour dietary recalls were obtained at an initial interview and again at a final interview after a nutrition education program, which was offered to a randomly selected treatment group. At the initial interview, the mean nutrient intakes that were most often below two-thirds of the Recommended Dietary Allowance (RDA) were iron, vitamin A, thiamin, and calcium. The mean energy value of the diets was also frequently below the RDA. At the final intakes, although the mean energy values and the calcium and carbohydrate of both the control and treatment groups increased significantly, the following improvements in dietary intakes were seen only within the treatment group: 1) there were significant increases in the mean intake of protein, ascorbic acid, niacin, riboflavin, and thiamin, 2) there were significant decreases in the percentage of intakes below two-thirds of the RDA for ascorbic acid and riboflavin, and 3) there was a significant decrease in the incidence of multiple low nutrient intakes. These dietary improvements, which occurred only in the treatment group, suggest the effectiveness of the nutrition education program. The most common biochemical deficiencies were of folic acid, thiamin, and riboflavin. Except for an improvement in mean serum folate levels, the biochemical indices for the treatment group did not appear to be influenced by the nutrition education. It is possible that the vitamin and mineral supplements which were taken by 80% of the women could have obscured improvements in biochemical indices which may have been due to the education program.