OBJECTIVES: The aim of the study was to investigate whether different types of health promotion intervention in the workplace reduce depression and anxiety symptoms. METHODS: A systematic review and meta-analysis of the literature was undertaken on workplace health promotion published during the period 1997–2007. Studies were considered eligible for inclusion if they evaluated the impact of an intervention using a valid indicator or specific measure of depression or anxiety symptoms. The standardized mean difference was calculated for each of the following three types of outcome measures: depression, anxiety, and composite mental health. RESULTS: Altogether 22 studies were found that met the inclusion criteria, with a total sample size of 3409 employees postintervention, and 17 of these studies were included in the meta-analysis, representing 20 intervention–control comparisons. The pooled results indicated small, but positive overall effects of the interventions with respect to symptoms of depression [SMD 0.28, 95% confidence interval (95% CI) 0.12–0.44] and anxiety (SMD 0.29, 95% CI 0.06–0.51), but no effect on composite mental health measures (SMD 0.05, 95% CI -0.03–0.13). The interventions that included a direct focus on mental health had a comparable effect on depression and anxiety symptoms, as did the interventions with an indirect focus on risk factors. CONCLUSIONS: When the aim is to reduce symptoms of depression and anxiety in employee populations, a broad range of health promotion interventions appear to be effective, although the effect is small.