Ninety per cent of smokers report having their first whole cigarette before the age of 19. Thus, it is important to have policies such as youth access laws which may prevent youth from becoming future smokers. In Canada, the Tobacco Act prohibits retailers from furnishing tobacco products to individuals under the age of 18. For such laws to be effective, however, it is important that retailers comply with them. The objective of this study was to examine the effect of retailer compliance on youth smoking behaviour. Data on individual smoking behaviour in conjunction with provincial retailer compliance rates and cigarette prices for the years 1999-2005 were employed to examine the effects of retailer compliance on youth smoking participation and consumption. Both price and retailer compliance were significant predictors of smoking participation. Price elasticity of demand for the overall sample was estimated to be -0.54. Our results which are consistent with previous research indicate that retailer compliance must be considered when examining the effects of youth access laws. This research confirmed that youth access laws can be an important component of a successful public policy approach to youth smoking prevention.