To establish the prevalence of liver enzyme alterations in the course of serious infections of diverse origin, 112 patients were studied retrospectively for the levels of GOT, GPT, LDH, GGT, alkaline phosphatase (FA) and bilirubin (BIL). Cases in which the values might be altered due to causes other than the infectious process were previously excluded. The prevalence of affectation of each of the parameters was the following: GGT, 39.1%; LDH, 33.3%; FAL, 30.1%; GOT, 29.5%; GPT, 24.8%; BIL, 18.3%. Seventy percent had at least one of these values changed. No significant differences were found in the incidence or intensity of the analytic alterations in function of the origin of the of infection, which suggests that these modification are nonspecific. Bilirubin levels were found to be significantly higher in the patients who died. On realizing the linear correlation analysis between the diverse parameters studied, a good correlation was found between them, suggesting a common pathogenetic mechanism.