Bilateral unicompartmental knee arthroplasty (UKA) may be performed as one- or two-stage procedure. Previous reports suggest that UKA provides a more rapid functional recovery than total knee arthroplasty. However, little data exist on whether bilateral UKA can be performed without increasing the perioperative risk compared with unilateral cases. We retrospectively compared 51 patients treated between January 2014 and March 2017 with single-stage UKA (group A) with 51 patients who underwent unilateral procedure (group B) to evaluate perioperative complications. We noted no statistically significant difference between the two groups in terms of gender, age and body mass index. Patients who underwent single-stage bilateral UKA had longer operating room time with respect to single procedure (93.2 min vs. 50.7 min). However, the bilateral group had a shorter cumulative operating room time (93.2 min) compared to the unilateral group (101.5 min) with a statistically significant difference (p < 0.05). Average hemoglobin loss at discharge was 3.1 points for group A and 2.4 for group B, with a statistically significant difference (p < 0.05). Our results demonstrated that bilateral simultaneous UKA does not increase the risk for perioperative complications. Total blood loss at discharge is statistically higher in bilateral UKA rather than unilateral UKA; however, cumulative hemoglobin loss is statistically lower in bilateral group. Patients can benefit from a single hospital admission and anesthetic time, while the shorter total inpatient stay and lower blood loss can reduce hospital costs in cases of bilateral surgery. Retrospective study.