Reducing maternal mortality remains a global priority, particularly in low- and middle-income countries (LMICs). The Safer Anaesthesia from Education (SAFE) Obstetric Anaesthesia (OB) course is a three-day refresher course for trained anaesthesia providers addressing common causes of maternal mortality in LMICs. This aim of this study was to investigate the impact of SAFE training for a cohort of anaesthesia providers in Ethiopia. We conducted a mixed methods longitudinal cohort study incorporating a behavioural questionnaire, multiple-choice questionnaires (MCQs), structured observational skills tests and structured interviews for anaesthesia providers who attended one of four SAFE-OB courses conducted in two regions of Ethiopia from October 2017 to May 2018. Some 149 participants from 60 facilities attended training. Behavioural questionnaires were completed at baseline (n = 101, 69% response rate). Pre- and post-course MCQs (n = 121, n = 123 respectively) and pre- and post-course skills tests (n = 123, n = 105 respectively) were completed, with repeat MCQ and skills tests, and semi-structured interviews completed at follow-up (n = 88, n = 76, n = 49 respectively). The mean MCQ scores for all participants improved from 80.3% prior to training to 85.4% following training (P < 0.0001) and skills test scores improved from 56.5% to 83.2% (P < 0.0001). Improvements in MCQs and skills were maintained at follow-up 3–11 months post-training compared to baseline (P = 0.0006, < 0.0001 respectively). Participants reported improved confidence, teamwork and communication at follow-up. This study suggests that the SAFE-OB course can have a sustained impact on knowledge and skills and can improve the confidence of anaesthesia providers and communication within surgical teams.