The purpose of this pilot cross-sectional study was to compare the operating room (OR) efficiency and intraoperative staff task load when performing individualised versus off-the-shelf (OTS) total knee arthroplasty (TKA). A consecutive series of 28 patients randomised (1:1) to receive either OTS TKA or individualised TKA were included. The OR staff workload was assessed with the NASA Task Load Index (TLX), a subjective grading system assessing mental demand, physical demand, temporal demand, performance, effort and frustration on a scale from 0 (very low) to 20 (very high). The time for patient preparation, surgical time, closureand total OR time was recorded to assess OR efficiency. Effect sizes of differences between OTS and individualised TKA were expressed as mean differences (MDs) with 95% confidence intervals (CIs). Patients in both cohorts were similar in age (OTS vs. individualised TKA (median [IQR]), 67 [63-76] vs. 71 [68-79]; p = 0.207) and body mass index (BMI) (29 [24-33] vs. 29 [26-31]; p = 0.807), and there were no significant differences in other preoperative characteristics. The OR staff perceived individualised TKA as less demanding than OTS TKA: Individualised TKA was rated significantly better across the six domains of the NASA TLX: mental demand by 5.6 points, physical demand by 6.3 points, temporal demand by 5.3 points, performance by 3.6 points, effort by 5.9 pointsand frustration by 5.8 points. Individualised TKA resulted in statistically significantly shorter mean total OR time (MD, 10 min; p = 0.018). The staff in the OR found that individualised TKA is less mentally, physicallyand temporally demanding than OTS TKA. The average total time spent in the OR during individualised TKA is 10 minless than during OTS TKA. This study constitutes a part of a larger registered randomised controlled trial comparing patient satisfaction following OTS versus individualised TKA (NCT04460989). Level III.