Mindfulness as a positive mental health intervention approach has been increasingly applied to nurses. This meta-analysis evaluated the psychological effects of mindfulness-based interventions (MBIs) on mental health in nurses. We searched PubMed, EMBASE, Cochrane, and CINAHL up to February 2020. Randomized controlled trials (RCTs) evaluating the effects of MBIs for nurses were included. Data extraction and the risk of bias assessment were conducted by two authors independently. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated using a random-effects meta-analysis. Of 370 studies retrieve from databases, nine RCTs, which involved 572 participants with 283 in an intervention group and 289 in a control group, were included in the final analysis. Compared to the control groups (no treatment, treatment as usual, or active control), MBIs reduced psychological distress such as anxiety, depression, or stress (SMD = -0.47; 95% CI, -0.67 to -0.32; I2 = 34.7; n = 17) in nurses. Also, MBIs slightly improved psychological wellbeing such as resilience, wellbeing, or quality of life (SMD = 0.28; 95% CI, 0.11 to 0.46; I2 = 0.00; n = 8). However, no statistically significant effects were found in Job related outcomes (SMD = 0.23; 95% CI, -0.01 to 0.47; I2 = 20.5; n = 6). This meta-analysis found that MBIs had beneficial effects on mental health such as psychological distress and wellbeing in nurses.