BACKGROUND: Despite the popularity of a ketogenic diet, no randomized, controlled trials have evaluated its efficacy on metabolic dysfunction-associated steatotic liver disease (MASLD) progression. METHODS: We conducted an 8-week, open-label, randomized controlled trial involving 24 patients with MASLD who were randomly assigned to either the home delivery ketogenic diet or a nutrition education program on adherence to the DASH diet. The primary outcome was a reduction in hepatic steatosis as measured by transient elastography. RESULTS: There were no significant differences between groups in liver stiffness and steatosis measurement after interventions. Subjects on a ketogenic diet had lost more weight than subjects in the control group at 8 weeks (mean change [95% CI], -6.16 [-7.22, -5.10] vs. -2.14 [-4.49, 0.21] kg; p = 0.001). The decrease in waist circumference, systolic blood pressure, fat mass, and visceral fat area was significantly greater among subjects on a ketogenic diet than among those in the control group. Laboratory parameters, including AST, triglyceride, and HDL were also significantly decreased among subjects on a ketogenic diet than among those in the control group. CONCLUSIONS: A ketogenic diet produced a significantly greater weight loss (absolute difference, approximately 4%) than did the general lifestyle advice intervention for the first 8 weeks. A ketogenic diet was associated with a greater improvement in some risk factors for coronary heart disease and MASLD. However, a ketogenic diet did not reduce steatosis nor worsen MASLD progression. Longer and larger studies are required to determine the long-term safety and efficacy of the ketogenic diet. Trial Registration: TCTR20220426005.