This study examined child and Family factors associated with the clinical referral of pervasively hyperactive children. Fourteen children with pervasive hyperactive behaviour problems referred to a London child guidance service were compared with 13 nonreferred pervasively hyperactive children resident in the same geographic area. Child behaviour, parenting, and Family life factors were examined as determinants of referral. Preliminary results suggest that both child and parenting factors play an important role in determining whether a child with hyperactivity will be referred for child guidance. The best predictors of clinical referral were a parent's ability to cope with child behaviour, child emotional disturbance, School relationship problems, and parental disciplinary indulgence. Implications of referral bias for research and service planning are discussed.