Background For elderly patients who are about to undergo surgery, research on the effects of preoperative medication on postoperative outcomes is rare, especially preoperative discontinuation-requiring medication (PDRM) which needed to be discontinued because of its increased risk of postoperative complications. Aim To investigate whether preoperative medication (PDRM and polypharmacy) is associated with postoperative length of hospital stay (LOS) in elderly patients undergoing hip fracture surgery. Methods Patients aged >= 65 who were scheduled for hip (limited to femoral tuberosity) fracture surgery were included. Baseline characteristics, preoperative medication and postoperative LOS were collected from the electronic medical record. The primary outcome was postoperative LOS. Results A total of 369 hip fracture patients were included. There were 188 and 122 patients exposed to PDRM and polypharmacy, respectively. Multivariate analysis models were constructed using significant factors for prolonged postoperative hospital stay from univariate analysis: Model I (body mass index (BMI), Charlson comorbidity index (CCI) >= 7, creatinine clearance rate (Ccr) < 60 and PDRM) and Model II (BMI, Ccr >= 7, Ccr < 60 and polypharmacy). CCI was the most significant factor. Its adjusted odds ratio was as large as 2.7 and attributable risk was 63%. In preoperative medication use, both polypharmacy and PDRM showed significant association with postoperative LOS. Conclusion The present study supported the impact of PDRM on postoperative LOS in geriatric hip fracture patients. The results added a further aspect to preoperative medication optimization in elderly patients undergoing hip fracture surgery.