The objective of this study was to compare efficacy and tolerability of the selective noradrenaline reuptake inhibitor reboxetine with the selective serotonin reuptake inhibitor citalopram, in the treatment of major depressive disorder (MDD). In total, 357 outpatients with MDD were randomized to treatment with reboxetine 8-10 mg or citalopram 20-40 mg per day during 24 weeks. Primary end-point was change from baseline in the Hamilton Depression Rating Scale (HAM-D, 21 items). Sexual function/dysfunction was measured by the Sexual Function scale (SF). Observed case analysis showed that both treatments yielded a gradual reduction of HAM-D scores: reboxetine with -21.4 and citalopram with -22.1 points (NS). LOCF analysis showed a greater reduction of the HAM-D scores with citalopram compared with reboxetine (-19.6 vs. -17.8; P = 0.034). The response rate was 90.3% for reboxetine and 92.7% for citalopram (NS). The most common side effect in the reboxetine group was dry mouth, and in the citalopram group sexual dysfunction. At week 24, anorgasmia was reported by 5.9% of the sexually active women in the reboxetine group vs 39% in the citalopram group. The dropout number was 91 in the reboxetine group, and 54 in the citalopram group. To summarize, both treatments gave a satisfactory antidepressant effect. The side effect profile differed between the groups, with a notably high prevalence of sexual dysfunctions in the citalopram group. The high number of dropouts in the reboxetine group, is considered as a result of the non-titration starting dose of 8 mg reboxetine per day, which gave a high incidence of early side-effects.