PurposeTo compare the outcomes and complications of two perioperative protocols for the management of patients who underwent medial unicompartmental knee arthroplasty (UKA): 24 h (1‐day surgery [OS]) versus 72 h (enhanced recovery after surgery [ERAS]) of the length of hospital stay (LOS). In our hypothesis, the reduction of the LOS from 3 to 1 day did not influence the outcomes and complications.MethodsA total of 42 patients (21 in each group) with isolated anteromedial knee osteoarthritis and meeting specific criteria were prospectively included in the study. Clinical outcomes included Knee Society Score (KSS) and Forgotten joint score while pain evaluation was performed using a Visual Analogue Scale (VAS). Functional outcomes were assessed measuring the knee range of motion (ROM) while radiographic outcomes were evaluated measuring the amelioration of the varus deformity through the hip–knee–ankle angle (HKA).ResultsClinical and functional outcomes did not significantly differ between the two groups. Complications occurred in 9.5% of OS and 4.7% of ERAS group patients. Significant improvements in knee ROM, VAS pain, KSS and HKA angle were observed postsurgery, with no significant differences between groups except in KSS expectations and function trends.ConclusionThe OS protocol is safe and effective and LOS, in a well‐defined fast‐track protocol, did not significantly impact clinical and functional outcomes. OS may lead to reduced hospitalisation costs and potential reductions in complications associated with prolonged stays, benefiting both patients and healthcare facilities. However, further research with larger sample sizes and longer follow‐up periods is needed to confirm these findings. Early mobilisation and rehabilitation protocols are key components of successful patient recovery following UKA procedures.Level of EvidenceLevel II.