We tested the hypothesis that patients with Prader–Willi syndrome (PWS) may be at lower risk of developing non-alcoholic fatty liver disease (NAFLD) because of a higher insulin sensitivity. Twenty-one PWS patients and 42 control subjects closely similar for age, gender, pubertal stage and body mass index (CNT), were studied. Metabolic profile and body composition were assessed. NAFLD was established by a validated method of US grading (range from G0 to G3). PWS patients showed a significantly better metabolic profile (lower waist circumference, fasting glucose levels, HOMA-IR, cholesterol, transaminase levels and trunk fat mass/fat mass ratio). Furthermore, NAFLD G1stage was significantly more frequent in PWS subjects (P < 0.05), whereas G2 stage was significantly more frequent in control patients (P < 0.05). NAFLD grading seems to correlate with body composition in PWS, also after adjustment for sex and GH treatment. To our knowledge, this is the first report suggesting a reduced risk of NAFLD in PWS children.