Circulating microRNAs (miRNA) have been widely recognized as a novel noninvasive biomarker in a variety of physiological and pathological conditions. In order to assess the sensitivity and reliability of potential miRNAs as diagnostic markers for liver disease related to viral infection, alcohol abuse, or chemical exposure, we collected serum samples from 326 participants and evaluated the single and combination diagnostic values of three serum miRNAs (miR-122, miR-125b, miR-192) compared with a conventional marker ALT. We found that serum miR-122 is significantly elevated in patients with active HBV. MiR-125b increased in HCV positive patients, whereas miR-192 and miR-122 were associated with chemical-induced liver injury. None of the aforementioned miRNAs were shown to increase significantly in alcohol-related liver injuries. Furthermore, we analyzed different combinations and found that a set of miR-122 and miR-125b enhanced the sensitivity of detecting liver injury. Among the 58 ALI/ALF patients, miR-122 responded more rapidly than ALT in successful treatments. Patients with spontaneous recovery from ALI/ALF showed significantly higher serum levels of miR-122 and miR-125b compared to non-recovered patients. In conclusion, our results suggest that the combination of miR-122 and miR-125b may serve as efficient biomarkers for liver injury and may be of a prognostic value in predicting ALI/ALF outcome.