Prenatal psychopathology may have an adverse impact on mother and baby, but few women receive treatment. We offered a 10-week mindfulness yoga (M-Yoga) intervention to psychiatrically high-risk pregnant women as an alternative to pharmacological treatment. Participants (N = 18) were primiparous, 12–26 weeks pregnant, and had elevated scores (>9) on the Edinburgh Postnatal Depression Screen at baseline. In addition to a baseline diagnostic assessment, women completed self-ratings on depression, mindfulness, and maternal-fetal attachment before and after M-Yoga. Findings suggest that M-Yoga was feasible, accepted and effective. Symptoms of depression were significantly reduced (p = 0.025), while mindfulness (p = 0.007) and maternal-fetal attachment (p = 0.000) significantly increased. Overall, this pilot study is the first to demonstrate that M-Yoga may be an effective treatment alternative or augmentation to pharmacotherapy for pregnant women at high risk for psychopathology.