Chinese people may have a higher rate of gambling problems than other cultural groups. However, there are very few clinical outcome studies that have demonstrated the effectiveness of clinical interventions for helping Chinese gamblers. Cognitive behavioural therapy (CBT) has been found to be effective for helping problem gamblers to significantly reduce their gambling problems in western countries. Very few CBT clinical trials have been conducted with the Chinese populations, and the results were masked by methodological limitations. This preliminary study attempted to test the effectiveness of an integrated and culturally attuned CBT group treatment for Chinese problem gamblers in Hong Kong. This study adopted a randomized control design and 38 participants were allocated randomly to the experimental condition (n = 18) and control condition (n = 20). The experimental group received 10 weekly CBT group sessions and individual counseling services while control group only received the individual counseling services. Significant decreases in gambling severity and frequencies of gambling were found in the experimental group. The findings also showed that a change in gambling cognitions predicted the changes in gambling severity and gambling urge while a change in gambling severity was also linked to a change in depression. Preliminary evidence highlights the potential benefits of an integrated and culturally attuned CBT group treatment for Chinese problem gamblers in Hong Kong. However, a more vigorous research design with a larger sample is needed to provide solid evidence of the effectiveness of the model for Chinese problem gamblers.