Classroom and playground behaviors of 95 integrated mildly intellectually handicapped and mildly disabled students were compared with those of 95 nonhandicapped, age- and sex-matched regular class students. All subjects attended state government primary schools and were between 8 and 13 years of age. Subjects' behavior was observed in the integrated classroom and in playgrounds by means of a time sampling method that contained 9 categories of classroom behavior and 9 categories of playground behavior. Data indicated that the behavior of the integrated mildly handicapped students was in many ways similar to that of their regular class peers. Both groups of students showed low levels of negative, disruptive, and aggressive behavior in the classroom and playground. The groups did not differ significantly in their amounts of interaction with adults or peers in the classroom. The groups' patterns of initiation with peers did not differ in either setting. But some differences were found between the groups' classroom and playground behaviors. Results are discussed in terms of theories of social acceptance and the influence of both individual and system factors on the successful integration of mildly disabled students. (RH)