The feeding behaviors of a child diagnosed with failure to thrive were assessed using descriptive analysis methodology to identify the schedules of reinforcement provided by the child's parents. This analysis revealed that the child's appropriate feeding behaviors (i.e., bite acceptance, self-feeding) were on a lean schedule of positive reinforcement and that the child's refusal behaviors (e.g., non-acceptance, expulsion) were on a rich schedule of negative reinforcement. A treatment package consisting of differential positive reinforcement for bite acceptance with and without escape extinction was evaluated by manipulating the schedules of reinforcement that were identified to be used by the child's parents. The results showed a reduction of the child's inappropriate mealtime behaviors and increases in the child's acceptance of offered food items. The results also suggested that the differential reinforcement component appeared to be most responsible for ongoing effectiveness of the treatment. These results are discussed in terms of treating the food refusal behavior of children diagnosed with failure to thrive as a preventive measure for later development of developmental disabilities.