The present study is concerned with selected factors that may strongly influence classroom teachers to refer young children for possible placement in special classes when the children are functioning near the borderline for placement on the basis of intelligence test scores. Particular attention was given to the contribution of student attributes (i.e., sex, ethnic background, socioeconomic status, and classroom behavior) and teacher attributes (i.e., age, sex, ethnic background and teaching experience) to the referral patterns of teachers. Also considered were the size of school enrollment, school locale, and interactions among student, teacher, and school variables. It was concluded that the teachers in the population studied responded to the case histories on the basis of certain selective biases. However, the relationship of these biases to referral decisions was less obvious and considerably more complex than has been suggested previously in the professional literature. At the same time, the presence of any bias in the referral process seemingly warrants careful consideration and points to the -need for greater emphasis in pre-service and in-service training programs upon the objective evaluation of students as an integral part of educational planning.