Objective: Diabetes mellitus (DM) and hypertension are both features of metabolic syndrome and hypertension is common among patients with DM. Clinical evidence suggests that modest sodium restriction has a hypotensive effect. We systematically reviewed published literature determining the effect of reduction in sodium intake on blood pressure (BP) in patients with DM. Methods: In June 2019, we searched PubMed, Embase, and Cochrane for randomized control trials (RCTs) assessing the effect of reduction in sodium intake on BP in DM patients published in English. Two reviewers screened titles, abstracts, and full-texts independently and assessed studies for inclusion and quality. Data on study design, patient characteristic, clinical efficacy, and risk of bias were extracted. Results: Of all the citations screened, 5 RCTs (2 crossover, 3 parallel) conducted in UK (3 RCTs), Netherlands (1 RCTs), and Germany (1 RCT) including 161 DM patients qualified for inclusion and assessed as low risk of bias. In patients with restricted sodium intake, a significant decrease in systolic BP was observed in 4 RCTs (3 from UK and 1 from Netherlands) consisting 145 Type 2 DM (T2D) patients [change ranged from -21.50 mm Hg to -4.2 mm Hg]. Similarly, a significant decrease in diastolic BP was observed in 3 RCTs (one each from UK, Germany, and Netherlands) consisting 87 patients [change ranged from -5.3 mm Hg to -1.7 mm Hg]. For remaining studies, patients on restricted sodium intake reported a decrease in both systolic (change -4.9 mm Hg) and diastolic BP (change -3.1 mm Hg), though statistically non-significant. Conclusion: Compared with regular diet, reduction in sodium intake was reported to have a statistically significant and clinically relevant reduction in systolic and diastolic BP in patients with DM. Generalizability of the current evidence from RCTs should be explored further due to the heterogeneity of population in included studies.