Using a unique data-set from the Pearl River Delta in China, we examine the factors associated with rural-urban migrants participation in and expenditure on illegal gambling. The characteristics that have the largest marginal effects on participation and expenditure are gender, whether one also participates in the legal lottery and playing mahjong and other card games. Of the variables specific to the migration experience, we find that living in a factory dormitory increases the probability of participating in the illegal lottery, and that migrants who are unwilling to give up their farmland are less likely to participate in the illegal lottery. We also find that having a network of female friends is negatively correlated with participation in the illegal lottery. However, other variables specific to migrants, such as willingness to obtain a local hukou and remittances, were found to have an insignificant effect on participation.