Background: Malnutrition is an urgent problem in the developing world, especially for children under 5 years of age. The article describes the utilization of a standard of practice designed to prevent illness in a malnourished, under-5 indigenous population and reinforced by weekly basic health messages taught by lay community health promoters. Method: The two villages were chosen for observation after administration of the standard of care among the Maya-Kíché, the most numerous Mayan group in Guatemala. The standard of practice, 20 mg of daily oral zinc, was administered for 10 days in the home and followed by daily vitamin supplementation that continued throughout the 3 months of the project. All patients received four monthly clinic visits, with one of the village groups receiving weekly health promoter visits. Results: Data evaluated after the quality improvement project showed significant differences in adherence to the zinc regimen (² = 3.677, p ≤ .05) as well as lower rates of diarrheal illnesses (² = 5.850, p ≤ .05), with both of these improved in the health promoter group. Discussion: This study suggests that the training and implementation of para–health professionals from the lay community in response to specific health care needs could be considered a best practice in developing countries. Implications: Public health professionals are key to health promoter training and direction, and their importance in the global setting cannot be understated.