OBJECTIVE: Legalized gambling opportunities have markedly increased in most industrialized countries. While most authors agree that the rate of pathological gamblers is related to the accessibility of gambling activities, no published studies have yet empirically estimated the impact of the introduction of new gambling activities within a longitudinal study. Thus, we evaluate the impact of the opening of a casino on gambling activities among nearby inhabitants. METHOD: A random sample of 457 respondents from the Hull area (experimental group) and 423 respondents from the Quebec City area (control group) completed the South Oaks Gambling Screen and related questions, both before the opening of the Casino de Hull and 1 year later. Within each household contacted, a resident was randomly chosen by selecting the adult whose birthday was next. RESULTS: The experimental group exposed to the new casino showed a significant increase in 1) gambling on casino games, 2) the maximum amount of money lost in 1 day on gambling, 3) reluctance toward the opening of a local casino, and 4) the number of participants who reported knowing a person who has developed a gambling problem in the last 12 months. CONCLUSION: The impact of legalized gambling is discussed in relation to the availability of gambling.