Background & aims: Plant-based diets have recently risen in popularity due to their proposed health benefits. We evaluated the association of plant-based diet quality with non alcoholic fatty liver (NAFL) prevalence and their interaction on risk for developing type 2 diabetes ten years later. Ethods: A post-hoc analysis of data collected in the ATTICA study. In 2001–02, 3042 participants from the Attica region of Greece were recruited. NAFL was assessed through hepatic steatosis index (HSI). Overall, healthful (hPDI), and unhealthful (uPDI) plant-based dietary indices (PDI) were calculated through standard procedures. N = 1485 participants free of type 2 diabetes at baseline completed the follow-up evaluation ten years later (n = 191 cases). Results: Unhealthy plant-based diet was significantly associated with likelihood for NAFL; the NAFL prevalence was 32.7%, 33.2% and 40.0%, respectively (p = 0.01), ranking from 1st to 3rd uPDI tertile. Multi-adjusted analysis revealed an inverse association between PDI and NAFL [OR(per 5 units increase in PDI) = 0.85 95%CI (0.76, 0.94)] and hPDI [HR(per 5 units increase in hPDI) = 0.91 95%CI (0.83, 0.99)] and a positive association in the case of uPDI [HR(per 5 units increase in uPDI) = 1.12 95%CI (1.01, 1.25)]. Multi-adjusted analysis revealed that baseline NAFL was associated with 2.95 times higher 10-year type 2 diabetes risk. No significant interaction of baseline liver steatosis with plant-based diet indices was observed (p for interaction > 0.05) in predicting type 2 diabetes. Conclusions: Plant-based diet quality is of importance for NAFL and affects long-term risk for incident type 2 diabetes.