Introduction and Objective. Several factors contribute to the duration of the hospital stay in patients that undergo to total hip arthroplasty (THA), either subjective or perioperative. However, no definite evidence has been provided on the role of any of these factors on the hospitalization length. The aim of this retrospective investigation is to evaluate the correlation between several preoperative and perioperative factors and the length of hospital stay (LOS) in patients that underwent elective total hip arthroplasty. Materials and Methods. Medical records of patients that underwent THA since the beginning of 2016 to the end of 2018 were retrospectively screened. Demographics, comorbidities, renal function, whole blood count. and length of post-operative ward stay were retrieved. The association between clinical, biochemical and surgical factors and the length of hospital stay was explored by means of linear regression models. Results. A total of 743 subjects were included. Retrieved comorbidity included arterial hypertension (47%), dyslipidaemia (20%), chronic kidney disease (CKD) (12%) and diabetes mellitus (9%). The median length of post-operative hospital stay was 4 days (IQR: 2). Variables associated with linear increase of hospitalization length were the estimated Glomerular Filtration Rate (eGFR) (Beta −0.01, 95% CI −0.02, 0), CKD (Beta 0.82, 95% CI 0.29, 1.34), duration of surgery (Beta 0.69, 95% CI 0.44, 0.94). After correction for multiple confounders, the CKD (a-Beta 1.58 95%CI 0.00 – 3.22) and operation time (a-Beta 0.67, 95% CI 0.42, 0.92) were consistently associated with the outcome. Conclusions. Our analysis demonstrated a significant role played by the eGFR (as an index of renal function) in influencing the length of hospital stay