Introduction:Inadequate hospitalizations (IH) alter hospital management and much more when they are carried out in the elderly population; therefore, identifying the factors is relevant at the national and local levels. Objective: To determine the factors associated with IH in older adults in the Emergency Service (ES) of the Edgardo Rebagliati Martins National Hospital (HNERM) during 2017. Methods: Observational, analytical, cross-sectional study. A sample of 414 patients randomly selected from 18 250 patients admitted during the study period was selected. Collection forms were used, and medical records were reviewed. With the help of the SPSS 25 program, the Chi-square test was performed, and the simple Prevalence Ratio (PR) and adjusted (Rpa) were calculated. The level of signicance was 5%. Results: The frequency of IH was 11,8%. The epidemiological factors associated with IH were age...