ABSTRACT Although corporate social responsibility (CSR) has been instrumental in achieving corporation’s competitive advantage, this is not the case for casinos. This study examines how CSR scepticism develops in the context of the casino industry by investigating the effects of customers’ attitudes towards casinos engaged in corporate social irresponsibility (CSI) and the controversy surrounding casino businesses on CSR scepticism, which leads negative word-of-mouth (WOM) and protest behaviour. To this end, 310 South Korean casino customers completed an online questionnaire. The results of partial least squares path modelling revealed direct effects of customers’ attitudes towards firms exhibiting CSI and the perceived controversy on CSR scepticism leading to negative WOM and protest behaviour. The impact of the attitude towards firms exhibiting CSI on CSR scepticism was found to differ between low perceived controversy and high perceived controversy customers. The findings suggest that casino companies should strive for transparency and develop appropriate CSR initiatives.