Introduction: I.C.U. is an area dedicated to integral attention of severe ill patients. Objective: To establish the epidemiological profile of patients admitted to adult I.C.U. of Hospital Universitario San Jose of Popayan, Colombia, 2012. To determine risk factors associated to mortality and most prevalent diagnoses. Methods: Descriptive, retrospective study of the epidemiological profile of patients admitted to I.C.U. After authorization from ethics committee, 949 patients selected from the database were studied. Variables were codified according to investigators criteria. Associations were established among variables and mortality and diagnoses using chi² to determine statistical significance (p<0.05). Unadjusted OR with a 95% CI was calculated to determine the level of association. Multivariate analysis was not performed for adjustment of established associations. Results: Male gender presented the higher admission frequency; mean age was 52.9 ± 21.9 years, with a median of stay of 4 days, and an interquartile range of 4. Mortality overall was 15%, with a 48 hours after admission mortality rate of 7.9%. Male gender and receiving ventilator support are factors associated with mortality in I.C.U. Gender, age and origin are factors associated with the most prevalent diagnoses. Conclusion: I.C.U. has a prevalence of male gender. Mortality trends show lower indices to what is reported in literature. The established mortality is associated to socio-demographic and clinic risk factors, with ventilator support the one with the higher association (confusion nonadjusted analysis). Most prevalent diagnoses are associated to risk factors that ratify what is referred in literature.