Tips represent a substantial portion of restaurant waiters' and waitresses' incomes. We report a study that examines several potential predictors of the differences in servers' average tip earnings. Our results indicate that servers earn larger average sales-adjusted tips if they are attractive females, better service providers, and high self-monitors. However, these effects hold up only for evening tips. None of the variables in this study predicted servers' average lunch tips. The methodological, theoretical, and managerial implications of these findings are discussed.