This article is concerned with the assessment of staff adherence to behavior management contingencies on a child psychiatric unit using a staff-patient interaction coding system. The Coding System for Staff-Patient Interactions (CSSPI), which draws upon the parent-child coding system described by Forehand and McMahon (1981), documents up to 10 interactions between staff members and child patients in each 30-second observation interval. The CSSPI includes several staff antecedents, child behaviors, and staff consequences. In this study, the interactions of 31 staff members were observed. The reliability of measurement was established in an analogue setting and on the unit. Descriptive findings showed considerable variability in the rates of individual interactions and the consistency with which appropriate staff responses were made to child behavior. Predictors of staff behavior included work history and nursing stress variables. The implications of these findings for ongoing monitoring and modification of the therapeutic integrity of child psychiatric units is discussed.