It has been suggested that deficits in emotional and social reciprocity may prevent children with autism from forming secure relationships to their mothers. The limited research available suggests that whilst children with autism can form relationships with the mother, they tend to experience a poorer quality relationship than typically developing children or children with intellectual disabilities. Expressed emotion (BE) is a measure ofthe emotional relationship between parent and child. EE can be divided into two constructs; criticism and emotional over-involvement (EOI). In the present study 100 mothers ofyoung children with autism completed questionnaire measures ofmaternal wellbeing (stress, mental health) and child characteristics (severity ofautism, pro-social and problem behaviour). Measures ofchild adaptive behaviour and maternal EE and warmth were collected during interviews with mothers. In 82 cases mothers also completed problem behaviour, EE and warmth measures for a typically developing sibling to the child with autism. The results indicated that criticism was associated with maternal stress and child behaviour problems. EOI was not significantly related to any maternal wellbeing or child variables. Warmth, however, was associated with the severity ofthe child's autism. Comparisons???? between sibling pairs indicated that mothers were more critical towards their child with autism than to the typically developing sibling. A marginally significant difference was also found for warmth, indicating that mothers were less warm towards their children with autism. Children with autism, therefore, appear to experience a poorer quality of mother-child relationship than their typically developing siblings. Implications for reducing EE and improving the relationship are discussed. As this is a relatively under researched area there is a clear need for further research to fully inform interventions.