AIMS:The impacts on the community of the opening of a casino in Niagara Falls are studied. DESIGN:The study uses a pre/post design for the community data, with pre/post data from Ontario as a whole as a comparison. SETTING:The study site is the city of Niagara Falls, Ontario, where a casino opened in early December, 1996. PARTICIPANTS:Using random-digit dialing, telephone interviews were conducted with adult residents of Niagara Falls in 1996 and 1997, and with adult residents of Ontario in 1995 and 1997. MEASUREMENTS:Aside from demographic variables, measures included general attitudes to gambling, expectations about (1996) and experiences with (1997) the casino's opening, extent of participation in 11 types of gambling and 18 items on problems with gambling: five key items from a standard gambling problems score (SOGS), five life-area problems items, and items on pressures from others concerning the respondent's gambling and on gambling problems among family and friends. FINDINGS:Attitudes to gambling remained stable in Niagara Falls, while there was some evidence of decline in approval in Ontario as a whole. While strong majorities of 1996 respondents had expected many positive and negative effects on The Community of the Casino's opening, Significantly fewer respondents in 1997 reported actually experiencing most of these effects. While a small increase in employment was found, it fell far below projections, a result probably reflecting displacement effects. The rate and level of casino gambling increased in Ontario, but increased even more in Niagara Falls, with little displacement of other gambling. Reported gambling problems increased significantly in Niagara Falls for two of 10 gambling problem items and for the short SOGS score, while rates were generally stable or declining in the province. Pressure from others about gambling rose significantly in Niagara Falls (in contrast to the province), and reported rates of family members or friends with gambling problems also rose substantially. There was an increasing trend in Niagara Falls for all 18 problem indicators. CONCLUSIONS:The casino's opening brought more gambling by local residents, and an increase in reported gambling problems; yet support for the casino, already strong, if anything grew. At least in the short term, problems from the increased availability of gambling manifested themselves not in the public arena but rather in the arena of private life.