Objective To analyze the roles of serum 7 microRNAs (7miRNAs, including miRNA-122, miRNA-192, miRNA-21, miRNA-223, miRNA-26a, miRNA-27a, and miRNA-801) alone or in combination with α-fetoprotein (AFP) in diagnosing hepatocellular carcinoma (HCC). Methods A total of 249 patients who were admitted to our hospital from Jan. 2021 to Jun. 2021 were enrolled, including 163 patients with confirmed HCC (HCC group) and 86 patients without HCC (non-HCC group). The serum levels of 7miRNAs and AFP were measured in the 2 groups, and based on the established clinical criteria (7miRNAs≥－0.5 and/or AFP≥20 ng/mL were positive), the sensitivity, specificity, positive predictive value and negative predictive value of the 2 indicators were calculated for the diagnosis of HCC alone and in combination. The receiver operating characteristic curve was used to analyze the diagnostic value of the 2 indicators used alone or in combination for HCC. Results Among 249 patients, the levels of 7miRNAs and AFP in the HCC group were significantly higher than those in the non-HCC group (both P＜0.01). The sensitivities of serum 7miRNAs, AFP and their combination were 75.46%, 57.06% and 87.12% for the diagnosis of HCC, respectively; the specificities were 74.42%, 94.19% and 69.77%, respectively; the positive predictive values were 84.83%, 94.90% and 84.52%, respectively; the negative predictive values were 61.54%, 53.64% and 74.07%, respectively; and the area under curve values were 0.787, 0.819 and 0.864, respectively. Conclusion The combined detection of serum 7miRNAs and AFP has higher diagnostic value than that of AFP used alone for HCC.