OBJECTIVE This review aimed to appraise clinical guidelines about exercise for women with gestational diabetes mellitus and summarize consensus and inconsistent recommendations. BACKGROUND Exercise is an effective non-pharmacological therapeutic for gestational diabetes mellitus, but the variety of relevant clinical practice guidelines is confusing for healthcare professionals. METHODS This is a systematic review of clinical practice guidelines. METHODS Websites of guideline development institutions, eight literature databases and organizations of obstetricians, gynaecologists, midwives, and medical sports associations were searched for guidelines published from January 2011 to October 2021. METHODS Two reviewers independently extracted recommendations. Four reviewers assessed guideline quality using the AGREE II instrument independently. RESULTS Fifteen guidelines were included. All women with diabetes are recommended to exercise during pregnancy. The consistent recommendations were for pre-exercise screening, for 30 min per exercise session on 5 days of the week or every day after meals, exercise at moderate intensity, using aerobic and resistance exercise, and walking. The main non-consistent recommendations included warning signs for women on insulin during exercise, minimum duration per session, intensity assessment, duration and frequency of sessions for strengthening and flexibility exercise and detailed physical activity giving birth. CONCLUSIONS Guidelines strongly support pregnant women with diabetes to exercise regularly. Research is needed to make non-consistent recommendations clear.