The aim of this study was to investigate the effects of probiotic yogurt consumption on some metabolic factors in nonalcoholic fatty liver disease (NAFLD) patients. This double-blind, randomized, controlled clinical trial was conducted on 72 patients with NAFLD (33 males and 39 females) aged 23 to 63 yr. Subjects in the intervention group (n=36) consumed 300g/d of probiotic yogurt containing Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 and those in the control group (n=36) consumed 300g/d of conventional yogurt for 8 wk. Fasting blood samples, anthropometric measurements, and dietary records (24h/d for 3 d) were collected at baseline and at the end of the trial. Probiotic yogurt consumption resulted in reductions of 4.67, 5.42, 4.1, and 6.92% in serum levels of alanine aminotransferase, aspartate aminotransferase, total cholesterol, and low-density lipoprotein cholesterol, respectively, compared with control group. No significant changes were observed in levels of serum glucose, triglycerides, or high-density lipoprotein cholesterol in either group. Probiotic yogurt consumption improved hepatic enzymes, serum total cholesterol, and low-density lipoprotein cholesterol levels in studied subjects and might be useful in management of NAFLD risk factors.