Background Disorders of attachment and social engagement have mainly been studied in children, reared in institutions and foster care. There are few studies amongst home reared children living with biological parents. The aim of this study was to test the clinical significance of inhibited attachment behaviour and disinhibited social engagement behaviour in young home reared children, referred for treatment of emotional and behavioural problems, compared with young children in treatment foster care. Methods The Disturbances of Attachment Interview, Maltreatment Classification System, the Child Behaviour Checklist and Parenting Stress Index were used in 141 referred home reared children and 59 referred foster children, aged 2.0–7.9 years (M = 4.7, SE = 1.3), 71% boys. Results Inhibited attachment behaviour was less prevalent in the referred home reared group (9%) than in the foster care group (27%). Disinhibited social engagement behaviour was found in 42% of the home reared group, similar to the foster care group. Inhibited attachment behaviour and disinhibited social engagement behaviour were not associated with child maltreatment. More inhibited attachment behaviour was associated with clinical levels of child internalizing and externalizing behaviour in the home reared group, not in the foster care group. In both groups, more disinhibited social engagement behaviour was associated with clinical levels of externalizing behaviour and with more parenting stress. Conclusions Even without evident links to maltreatment, results of this study suggest clinical significance of inhibited attachment behaviour and disinhibited social engagement behaviour in young home reared children referred for treatment of emotional and behavioural problems.