This study aimed to examinethe complications by comparing two surgeons simultaneous bilateral total knee arthroplasty (two-surgeon bilateral TKA) to one surgeon sequential bilateral total knee arthroplasty (single-surgeon bilateral TKA). Two hundred forty-six participants were prospectively randomized into two groups: two-surgeon bilateral TKA and single-surgeon bilateral TKA. While two surgeons performed simultaneous total knee arthroplasty in the two-surgeon bilateral TKA group, one surgeon performed sequentially in the single-surgeon bilateral TKA group. Ninety-day major, and minor complications rate, operative time, estimated blood loss (EBL) and patient-reported outcome measures were analysed. The two surgeons operated in two-surgeon bilateral TKA group 246 knees in 123 patients, while the single surgeon operated in single-surgeon bilateral TKA group 246 knees of 123 patients. The median operating time was 120 (range 70-151) minutes in the two-surgeon bilateral TKA group and 140 (range 75-190) minutes in the single-surgeon bilateral TKA group (p< 0.001). The median EBL was higher in the two-surgeon bilateral TKA group (p< 0.001). The 90-day complications were two major complications (1.6%) in the two-surgeon bilateral TKA group and 11 (8.9%) in the single-surgeon bilateral TKA group (p= 0.01). Two-surgeon simultaneous bilateral TKA is a safe method with lower complication rates compared with single-surgeon sequential bilateral TKA and can be preferred for experienced teams. However, peri- and post-operative care is required to decrease the risk of bleeding, particularly in patients undergoing two-surgeon simultaneous bilateral TKA. This study was retrospectively registered in a public trials registry ( https://clinicaltrials.gov/ , NCT04299516).