[Objective]: To compare the postoperative outcomes of cementless total knee arthroplasty (TKA) with cemented TKA through a large-scale retrospective analysis. [Methods]: A retrospective analysis was conducted using data from a major U.S. medical records database PearlDiver, covering 103,231 cases of knee osteoarthritis patients who underwent TKA between October 2015 and October 2020. The rates of medical complications within 90 days and surgical complications within 2 years postoperatively were compared between the two groups. Results: The transfusion rate within 90 days post-surgery was significantly higher in the cementless group compared to the cemented group (2.33% vs. 1.90%; OR 1.24, p<0.001). However, the incidence of deep venous thrombosis was lower in the cementless group (2.86% vs. 3.17%; OR 0.89, p=0.032). There were no statistically significant differences in other medical complications, such as pneumonia and pulmonary embolism. Within 2 years post-surgery, the rate of aseptic loosening of the prosthesis was lower in the cementless group compared to the cemented group (1.84% vs. 2.11%; OR 0.87, p=0.031). Rates of wound complications, periprosthetic infection, joint stiffness, periprosthetic fractures, and revision surgeries showed no significant intergroup differences. [Conclusion]: In primary TKA, patients receiving cementless TKA are at a significantly higher risk of perioperative blood loss compared to cemented TKA, but they are likely to experience a relatively lower risk of aseptic prosthesis loosening postoperatively. Between cementless and cemented TKA, no significant differences exist on risks of periprosthetic infection, revision surgery, or other complications.