Background: The gold standard for diagnosis of diabetes gastroparesis (DG) is with gastric emptying scintigraphy (GES) examination. However, GES is not available in every healthcare center worldwide and the examination cost is rather expensive, unlike ultrasonography (USG) examination. This study aims to evaluate gastric changes monitored with USG in diabetes mellitus (DM) and DG. Methods: We performed searches from Google Scholar, PubMed, Science Direct, Proquest, and Scopus in April 30 – May 6, 2022. Random-effect approach on outcomes, standardized mean-difference (SMD) and 95%-confidence interval (CI) was assessed. Results: Compared to healthy control; (1) Antral cross-sectional area (CSA) in DM is bigger in fasting (SMD=1.25cm2; 95%CI, 0.79 to 1.71, I2=81%, P<0.05) and postprandial (SMD=3.70 cm2; 95%CI, 1.45 to 5.34, I2=85%, P<0.05). (2) Gastric emptying time (GET) is longer with DG (SMD=75.44min; 95%CI, 31.61 to 119.27, I2=97%) and in DM (SMD=35.54min; 95% CI, 11.49 to 59.60, I2=94%). (3) Gastric half-emptying time (GE50) were found to be longer in DM (SMD=20.73 min; 95%CI, 14.69 to 26.77, I2=60%, P<0.05) and DG (SMD=7.46min; 95%CI, 5.06 to 9.86, I2=68.2%, P<0.05). (4) Smaller gastric emptying rate (GER) in DG (SMD=-31.95%; 95%CI, -42.22% to -21.69%, I2=84%, P<0.05) and DM (SMD=-16.14%; 95%CI, -30.88% to -1.39%, I2=78%, P<0.05). (5) Less antral contraction in DG (SMD=-1.47; 95%CI, -2.61 to -0.33, I2=82%, P<0.05). Conclusions: Patients with DM and DG have wider antral CSA, longer GET and GE50, reduced GER and reducing antral contraction. USG is useful for assessing gastric emptying in DM and DG. PROSPERO registration: CRD42022328695 (10/05/2022)