Pennsylvania pediatricians were interrogated through a questionnaire about their referral practices with and attitudes toward mildly and moderately delayed preschool children. Whereas most sought a diagnostic evaluation for those children functioning at half their chronological age, they did not refer less seriously retarded youngsters during the preschool years, despite favorable support for early intervention. The reluctance to diagnose and label may result from pediatricians' perceptions of what mental retardation means. For the most part, the respondents have the view-at variance with major organizational definitions-that retardation implies neurological dysfunction and a chronic irreversible status. Low IQ secondary to emotional or social conditions, on the other hand, is not perceived as retardation, and is considered remediable. The attitudes and practices are discussed in light of empirical research outcomes with handicapped children and the fixity of organically determined deficits.