Studies on specific language impairments (SLI) have demonstrated that SLI aggregate in families. This may be due to the presence of prenatal and postnatal features of a shared environment, such as parental smoking, that has been associated with lowered cognitive and language outcomes in children of smokers. This study explored the relationship between parental smoking and specific language impairments (SLI) in children. Using a case-control design, data on 177 children with SLI and 925 children who were typically developing were collected using a parental questionnaire concerning parental smoking habits. Maternal and paternal smoking during pregnancy, during children's development and continuous smoking during pregnancy and development were significantly related to SLI. However, when parental education was controlled for, these significant associations no longer existed. It is suggested that parental smoking, although not independently associated with SLI, may be an indicator of a parenting environment that places children at risk for language impairments.