Bariatric surgery reduces nonalcoholic fatty liver disease (NAFLD). We investigated the effects of duodenal-jejunal bypass liner (DJBL), nonsurgical bariatric device, on plasma parameters of NAFLD. Seventeen obese subjects with type 2 diabetes received the DJBL for 24 weeks. Before, during, and after DJBL implantation, we determined plasma levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), γ-glutamyltransferase (γ-GT), albumin, caspase-cleaved cytokeratin-18 (CK-18), and liver fatty acid-binding protein (L-FABP). At baseline, subjects had increased levels of AST (35 ± 4 IU/L), ALT (54 ± 5 IU/L), and γ-GT (66 ± 14 IU/L), compared with healthy individuals; subjects’ mean concentrations of caspase-cleaved CK-18 and L-FABP were 214.4 ± 35.6 U/L and 29.3 ± 2.6 ng/mL, respectively. Three months after implantation of DJBL, all NAFLD-related parameters had decreased from baseline (AST, 28 ± 3 IU/L; ALT, 32 ± 2 IU/L; γ-GT, 44 ±7 IU/L; caspase-cleaved CK-18, 140.6 ± 16.3U/L; and L-FABP, 18.2 ± 1.5 ng/mL; all P < .05). After 6 months, levels of ALT and γ-GT had further decreased (ALT, 28 ± 2 IU/L and γ-GT, 35 ± 5 IU/L), whereas levels of AST, caspase-cleaved CK-18, and L-FABP had stabilized (P = not significant). Six months after DJBLs were removed, levels of ALT (37 ± 3 IU/L), γ-GT (42 ± 5 IU/L), and caspase-cleaved CK-18 (124.5 ± 12.5U/L) were still reduced (P < .05), whereas AST and L-FABP had returned to near baseline levels (P = not significant). Therefore, in obese subjects, DJBL reduces plasma parameters of NAFLD. ClinicalTrials.gov, Number: NCT00985114.