A few reports have addressed the sex-related efficacy of deep brain stimulation (DBS) in the subthalamic nucleus (STN) to treat advanced Parkinson disease (PD). The present study evaluates the sex-related prognostic factors for STN-DBS outcomes. Seventy-two consecutive patients (48 men and 24 women) were reviewed retrospectively. Changes in the Unified PD Rating Scale scores were compared between men and women in the 6-month drug-off/DBS-on state relative to the preoperative drug-off baseline. A multivariate linear regression model was used to identify the preoperative factors predictive of motor improvements after surgery. Before surgery, the male and female patient groups were comparable in clinical severity, except the women were associated with slightly inferior cognition (P < 0.05) and a relatively better response to levodopa (LD) (P < 0.05) than the men. Both sexes showed similar clinical improvements after STN-DBS therapy. In men, preoperative lower LD requirement and higher motor dysfunction, particularly tremor (adjusted R(2) = 0.613, P < 0.001), as well as greater improvement in tremor and rigidity after LD therapy (adjusted R(2) = 0.232, P = 0.001) were favorable predictors of surgical outcomes. Women achieved a significant improvement if they performed well in activities of daily living even with higher baseline motor scores (adjusted R(2) = 0.620, P < 0.001), or exhibited improvements in akinesia disability after preoperative LD therapy (adjusted R(2) = 0.305, P = 0.003). STN-DBS therapy is equally beneficial for both sexes. Sex-related differences exist with regard to favorable prognostic predictors for early surgical outcomes.