Introduction: This study aimed to analyze the average length of stay of all inpatients in the department of Orthopaedics and to compare the variations in hospital stay between age, gender, traumatic and non-traumatic co-morbidities and modality of payment. Methods: This hospital based retrospective descriptive epidemiological study was based on patients discharged from a tertiary level health care center of eastern Nepal. Registry data of 1 year was used to calculate length of stay and analyze the variations. Results: Average length of stay was 10.5 days. It was 10.7 days for males and 10.1 days for females. It was 10.12 days for patients paying themselves for their treatment whereas 14.98 days for patients receiving reimbursement (third party payment). Conclusions: Average length of stay was more in elderly and patients of trauma (longest in pelvis injury). It was 1.5 times longer for patients receiving reimbursement for treatment.  Keywords: length of stay; non-traumatic co-morbidities; trauma; third party payment.