Rheumatoid arthritis patients exhibit a considerable interindividual variability in response to drug treatment. Although many disease-related and demographic factors have been studied to predict treatment outcome, the effective disease-modifying antirheumatic drug (DMARD) therapy is not yet allocated based on factors that predict efficacy. Individual genetic characteristics are thought to play an important role in treatment response; therefore, current research aims to identify these genetic predictors for clinical response. Pharmacogenetic studies are beginning to provide results, which suggests that personalized treatment maximization of DMARD efficacy and minimization of adverse drug reactions are feasible.