Introduction: The only treatment for grade IV knee osteoarthritis is total knee arthroplasty (TKA) irrespective of the age of the patient.Most of the grade IV OA patient are elderly and most likely to have some comorbidities. Age and comorbidities are the major reasons for patient’s reluctance toundergo TKA. A clinical pathway with standard length of stay(LOS) could justify the patient’s hesitation for TKA. The aimof this study was to determine the factors, including age andcomorbidity, that affect the LOS of patients treated with TKA. MaterialsandMethods:This is a retrospective study ofTKA patients in Surabaya Orthopedics and TraumatologyHospital from January 2011 to July 2017. Preoperativecomorbidities were scored using Charlson ComorbidityIndex (CCI) and physical status by ASA (American Societyof Anesthesiologist), classification for age, sex, BMI, bloodloss, operation time, method of anaesthesia andpostoperative day of rehabilitation were recorded as factorspotentially affecting LOS. The discharge criteria for thepatients were ability to ambulate to the bathroom and cleanoperative wound with no complications. The data obtainedwere analysed statistically.Results:The average LOS was 5.58 days, ranging fromthree to eight days. There were no demographic factors thataffected the patients’ LOS. BMI, ASA, CCI, and blood lossdid not significantly affect LOS. Operation time wasbetween 90-140 minutes, and spinal anaesthesia showedsignificant longer LOS, but within the average.Conclusion:Age and comorbidity did not affect length of stay in TKA patients.