The aim of the present study is to examine age-varying and long term associations between parental monitoring, involvement with deviant peers and substance use in a sample of adolescents followed from 12-17 years of age. The sample is drawn from the Malmö Individual and Neighbourhood Development Study (MINDS) and constitutes of four waves of data collection with 190 adolescents and their parents. OLS analyses were conducted to examine whether the associations between the study variables differ by age group. The sobel method was used for testing the significance of indirect effects. A longitudinal path-model was also specified and estimated to examine whether there are long term effects of parental monitoring on involvement with deviant peers and substance use. The main findings in the study show that the effect of parental monitoring on substance use is significantly mediated through involvement with deviant peers in all age groups. Further, the results show that parental monitoring in early adolescence is associated with substance use in later adolescence in different ways, mainly through involvement with deviant peers.