Objective: To help mitigate potential gambling harm, responsible gambling information centres are launching across casino venues in North America. The launch of the first such centre in the USA provided an opportunity to achieve three goals: (1) document the centre's reach among casino patrons, (2) generate a comprehensive description of services provided, and (3) explore the potential for a dose-response relationship between centre exposure and gambling beliefs and behaviour. Design: We documented services provided and surveyed consecutive centre visitors. Setting: We achieved these goals at the GameSense Info Center, located in the first Massachusetts casino. Method: Programme staff recorded their services via electronic checklist and administered one-page surveys to visitors with whom they discussed problem or responsible gambling. Results: Programme staff reported engaging directly with approximately 1% of daily patrons. About 70% of their interactions were casual. During conversations that did move beyond a casual nature, programme staff typically provided information about responsible gambling, consistent with patrons' self-reported needs and concerns. Finally, among a sample of patrons who repeatedly engaged with programme staff at the most involved level (N = 129), those with relatively little programme exposure were more likely to hold an accurate gambling belief but less likely to report having set time limits on their casino visits. Conclusion: We did not observe support for the notion that using an on-site information centre to teach patrons about important gambling concepts is associated with more responsible gambling behaviour.