Stillbirth is a significant global health problem that frequently results in perinatal grief with compound negative psychosocial impact. In low-resource settings with exceedingly high stillbirth rates, such as rural Chhattisgarh, India, it is vital to utilize low-cost, effective interventions. Mindfulness-based stress reduction is an evidence-based intervention utilized for a broad range of physical and mental health problems, and is adaptable to specific populations. The objective of this study was to explore the sustained effectiveness of a shortened, culturally adapted mindfulness-based intervention (MBI) designed to address complex grief after stillbirth. We used an observational, mixed-methods pre-post study design with 6-week and 12-month follow-up assessments among women with a history of stillbirth (N = 22). Analyses explored study outcomes and continued use of mindfulness skills. Pretest results showed elevated psychological symptoms and high levels of perinatal grief. General linear modeling repeated measures was used to explore 6-week and 12-month follow-up changes from baseline, controlling for significantly correlated demographic variables. Longitudinal results indicated significant reductions in perinatal grief and psychological symptoms; four of the five facets of mindfulness changed in the desired direction; and resilience scores indicated thriving. The shortened, culturally adapted, MBI pilot brought about sustained, significant reductions of perinatal grief and mental health symptoms, and participants reported use of mindfulness skills in day-to-day life. This study shows that the significant mental health needs among rural women of various castes and ethnicities in Chhattisgarh following stillbirth were successfully addressed by a promising MBI with potential scalability and sustainability.