Objective: Sertraline may produce dual neurotransmitter effects similar to the serotonin-norepinephrine reuptake inhibitors (SNRIs); however, it has been tested against an SNRI in only 1 previous study, and never at an optimal dose. The objective of the current multisite study was to compare relatively higher doses of sertraline (i.e., 150 mg/day) and venlafaxine extended release (XR) (225 mg/day) in outpatients with major depressive disorder. Method: Subjects with DSM-IV major depressive disorder were randomly assigned to 8 weeks of double-blind treatment with sertraline (N = 82) or venlafaxine XR (N = 78). The study ran from January 2002 through January 2003. The primary outcome measure was the Quality of Life Enjoyment and Satisfaction Questionnaire; secondary outcome variables included the 17-item Hamilton Rating Scale for Depression. Results: Both treatments led to significant improvement in depressive symptoms and quality-of-life measures. No significant differences were noted between treatment groups for final scores on the primary or secondary measures. The treatment groups did not differ significantly in the percentage of responders (sertraline = 55%, venlafaxine XR = 65%; intent-to-treat [ITT] sample) or remitters (sertraline = 38%, venlafaxine XR = 49%; ITT sample), although the proportions are similar to those found in earlier selective serotonin reuptake inhibitor (SSRI) vs. venlafaxine meta-analyses. In patients who achieved the maximum dose of drug and maintained it for 3 weeks, response rates were similar to those found at lower doses (sertraline = 59%, venlafaxine XR = 70%); however, remission rates for this sample were comparable for both drug groups (sertraline = 48%, venlafaxine XR = 50%). Conclusions: The efficacies of sertraline and venlafaxine XR were comparable. Although response and remission rates did not differ statistically, the rates were analogous to those reported in previous meta-analyses. However, at clinically relevant higher doses, the remission rates were very similar.