This report examined the effect of observer presence and absence on teacher behavior in the classroom. The study involved two undergraduate teachers in a preschool classroom serving eight children with special problems. Observations were made during a 45-minute work-play period when one of the teachers was in the play area. One observer recorded the teacher's behaviors behind a one-way mirror; the other observer was present in the classroom for 10 minutes of the 20-minute observation period. Records were kept continually throughout the play period by the observer behind the glass. In this study, physical contact was the teacher behavior observed, and was noted under one of the following categories: (a) teacher physical contact to appropriate child behavior, and (b) teacher physical contact to innappropriate child behavior. When the teachers were asked to increase physical contact with the children, the results showed that teachers carried out the request more when the observer was present than when absent. (A list of references and a set of tables indicating the sequence of experimental conditions and percentage of physical contact are included.) (JS)