This study investigated parent attitudes toward mainstreaming their handicapped children five years after Michigan's Special Education Act mandated parent involvement in the educational planning and placement process, and emphasized mainstreaming as the preferred alternative in the continuum of educational placements to be made available to handicapped children. The focus of this study was on the examination of those variables that appear to be related to the parents' preferred educational placement for their handicapped child. More specifically, the decision by the parents to place or not place their child in the mainstream of education was examined. Demographic variables such as age, sex, impairment of the child, race, income, and education of the parents were examined in relationship to parents' preferred class placement for their children. The parents' membership in parent organizations, and the predicted adult dependence-independence of the child as well as other variables such as the current placement of the child and the parents' feelings about the child's current placement were also examined for their relationship to the parents' preference for a mainstreaming placement for their child. A questionnaire was developed and mailed to members of five parent organizations in Washtenaw County, Michigan, plus 50 additional families. One hundred seventy-six parents responded yielding a response rate of approximately 45%. These parents formed a relatively homogeneous sample: highly educated, relatively affluent, 89% white. The children represented all handicaps as described by law except Visually Impaired. In place of a question on the severity of the handicap, parents were asked to try to predict the child's adult functioning from relatively independent to relatively dependent. Children of all levels of functioning were included. The results of the study indicated that parents tend to prefer a mainstreaming placement for their child - at least part-time (52% of the respondents). However, 25% of those parents whose children were currently in the mainstream full time wanted them mainstreaming only part-time. Twenty-one percent of those parents whose children were currently mainstreamed only part-time wanted them mainstreamed full time. and 29% of those parents whose children were currently in a special school full time wanted them moved closer to the mainstream. The decision to mainstream a handicapped child is a complex one. Rather than merely expressing a general approval of some abstract concept called mainstreaming, this study has found that parents have some definite attitudes about mainstreaming as it affects or could affect their own child. These attitudes are based on some characteristics of the child (as perceived by the parents), the parents' experience with specific educational placements, and the parents' feelings about their child's self-concept in a range of possible educational placements. Those variables which indicated a high predictive relationship with the parents' preferred placement for their child were: the child's current educational placement, the parents' prediction of the child's potential adult independence, and the parents' feelings about the child's current placement. In addition, the parents tended to choose a placement if they felt the child would have a positive self-concept in that placement and rejected a placement if they felt their child would not feel good about himself/herself in that situation. These results held true regardless of the nature of the child's handicap.