Results of a 1968 pilot study of the nutritional status of Mexican American preschool children in East Los Angeles and San Diego are reported in this document. Questionnaire data collected from mothers of preschool children are presented in terms of a description of families, prenatal care, clinical examinations, dietary intakes, and biochemical determinations. (Sample sizes ranged from 8 to 41 children, depending on the intended study variable.) The study indicated, for example, that these children had adequate intakes of protein, riboflavin, ascorbic acid, and niacin but that iron intakes were low. (JB)