Summary Objective Diagnosis of acute hepatitis C (AHC) relies on documented positive-seroconversion of antibody to hepatitis C virus (anti-HCV) that is infrequently encountered. To clarify the epidemiology and clinical course of AHC, we tried to find more AHC patients from a computerized laboratory database by using a supplemental criterion of rising anti-HCV titer. Methods All the computerized laboratory databases of anti-HCV and alanine aminotransferase (ALT) were reviewed. Candidates for AHC were identified by either anti-HCV positive seroconversion, rise of anti-HCV titer (signal to cut-off ratio (S/CO) ratio <40 to ≥40), or spontaneous HCV RNA clearance. AHC cases and their matched chronic hepatitis C controls were interviewed by a case–control study concerning risk factors. Results AHC was identified in 123 patients (68 men and 55 women; median age: 48.4 ± 13.9 years), who had higher rates of recent surgery ( p = 0.037) and frequent injection therapy ( p = 0.036) compared to controls. Self-limited AHC was observed in 18 (19.1%, 95% confidence interval: 12.3–25.9%) of 94 AHC patients who had been followed for 6 months, with a higher bilirubin level (≥2 vs. <2, p = 0.007) compared to those evolved to chronic infection. Conclusions Screening of a laboratory database for anti-HCV and ALT might uncover more AHC candidates to disclose the epidemiology and clinical course of AHC.