BACKGROUND: To determine the factors associated with inappropriate admissions in an Internal medicine department. SUBJECTS AND METHOD: We included 1,993 admissions. The justification for the admissions was evaluated using the Appropriateness Evalutation Protocol. RESULTS: 187 (9.4%) admissions were considered inappropriate. The likelihood of an inappropriate admission was higher as long as the patient was younger than 65 years of age (OR, 1.94; (95%) IC, 1.32-2.85) and the admission had been programmed from the outpatients clinic (OR, 10.58; (95%) IC, 2.79-40.1). Clinical diagnosis also influenced the inappropriateness of admissions. CONCLUSION: Age, diagnosis and source of patients determine inappropriate admissions in an internal medicine department.