This study examined associations between the gambling attitudes and behavior of 213 young adults and their perceptions of the gambling attitudes and behavior of their closest grandparent. Regression analyses showed that young adult gambling attitudes mediated the relations between perceived grandparent gambling attitudes and behavior and young adult gambling behavior. Grandparent–grandchild relationship quality experienced while growing up did not moderate the relations between young adult and perceived grandparent gambling attitudes and behavior. Men experienced gambling at a younger age and reported more positive gambling attitudes, more frequent gambling activity, higher levels of gambling pathology, and higher levels of gambling affinity than women. Implications of results and suggestions for future research are discussed.