Objectives: The objective of this systematic review and meta-analysis was to examine controlled trial evidence for the effectiveness of mindfulness-based interventions on stress, anxiety and depression in the perinatal period in women without pre-existing mental health issues. Methods: Six databases were searched for studies exploring the effects of mindfulness-based interventions on mental health outcomes of women during the perinatal period. Quality of both controlled trial meeting inclusion criteria were assessed using a tool specifically designed for meta-analyses of mindfulness-based interventions. Effect sizes were extracted for measures of mindfulness, depression, stress and anxiety outcomes. Effects were pooled in separate meta-analyses for all outcomes except anxiety which lacked sufficient studies. Results: Twelve studies were analysed. Pooled effects suggest that mindfulness-based interventions cause small but clear increases in mindfulness and reductions in depression in women without pre-existing disorders. Effects of mindfulness-based interventions on other outcomes were unclear and confounded by heterogeneity. Conclusions: Available controlled trial evidence suggests that mindfulness-based interventions improve mindfulness and decrease symptoms of depression during pregnancy in women without pre-existing mental health issues and might be a useful approach to prevent or attenuate the development of depression in the perinatal period.