Objectives: To test the potential impact of a critical curriculum on psychiatric medications designed for child welfare workers. Method: In a quasiexperimental, longitudinal study, the monthly proportion of medicated foster children and the average number of prescriptions per medicated child at Agency 1 (669 clients) exposed to the "CriticalThinkRx" curriculum were compared to Agencies 2-9 (3,346 clients) in the same two-county service network. Data were collected during 6 months of preintervention, 1 month of intervention, and 9 months of postintervention. Practitioners were not informed of data collection. Results: During postintervention months 1-8, the proportion of medicated children declined from 17.5% to 11.0% at Agency 1, while the mean proportion rose slightly at Agencies 2-9, statistically significant effects. At 9 months, the proportion at Agency 1 rose again though not reaching preintervention level. Average numbers of prescriptions per child remained unchanged. Conclusion: Use of "CriticalThinkRx" may reduce psychiatric prescribing in foster care. (Contains 3 tables and 2 figures.)