Simple SummaryWith the increasing prevalence of obesity and diabetes in most countries, the increase in hepatocellular carcinoma (HCC) associated with these factors has recently become a serious healthcare problem. HCC can often emerge in the non-cirrhotic liver among obese patients, and it might suggest that the conventional surveillance strategies for HCC, which is mainly targeted at cirrhotic patients with hepatitis B or C virus, might be insufficient in the overnutrition era. We tried to extract factors that affect recurrence-free survival in patients with non-viral HCC, among obesity and diabetes factors, together with the established recurrence risk factors, using a decision-tree analysis.We investigated the factors affecting recurrence-free survival in patients with non-B non-C hepatocellular carcinoma (HCC) who received curative treatment. Decision-tree analysis was performed in 72 curative cases of non-B non-C HCC to extract the risk factors for recurrence. The reliability of the extracted risk factors was evaluated using the Kaplan–Meier method and the Cox proportional hazards model. The decision-tree analysis extracted three factors—visceral adipose tissue (VAT) index (VATI; <71 and ≥71 cm2/m2), which was the cross-sectional areas of VAT on the computed tomographic image at the umbilical level, normalized by the square of the height, fasting immunoreactive insulin (FIRI; <5.5 and ≥5.5 µU/mL), and alpha-fetoprotein (AFP; <11 and ≥11 ng/mL). The Cox proportional hazards model showed that VATI (hazard ratio (HR): 2.556, 95% confidence interval (CI): 1.191–5.486, p = 0.016), FIRI (HR: 3.149, 95% CI: 1.156–8.575, p = 0.025), and AFP (HR: 3.362, 95% CI: 1.550–7.288, p = 0.002) were all independent risk factors for HCC recurrence. Non-B non-C HCC patients with a higher VATI (≥71 cm2/m2) or higher FIRI (≥5.5 µU/mL) and AFP (≥11 ng/mL) if VATI was <71 cm2/m2 are prone to recurrence after curative treatment.