Introduction: Total knee arthroplasty is a commonly performed procedure with postoperative complications including blood loss, pain, and hematoma formation. The role of intra-articular drainage in reducing these complications remains controversial. This study aims to evaluate the effects of intra-articular drainage on hemoglobin levels, pain, hematoma formation, and the need for blood transfusion in patients undergoing knee replacement. Materials and Methods: A prospective study was conducted on 60 patients divided into two groups: Drainage (D) and No Drainage (ND). Hemoglobin levels, pain scores, ultrasound evaluation of intra-articular hematoma, and transfusion rates were recorded on the first, third, and fifth postoperative days. The estimated blood loss was calculated using the Meunier formula. Pain was evaluated using the Visual Analog Scale, while hematoma size was measured using ultrasound. Results: The postoperative hemoglobin drop was significantly higher in the D group ( p = 0.0027), with a mean estimated blood loss of 1366 mL in the D group compared to 957 mL in the ND group. Four patients in the D group required blood transfusions, while none in the ND group did ( p = 0.0003). Pain scores were lower in the D group on the first postoperative day ( p = 0.0001), but no significant differences were observed on the third and fifth days. Ultrasound showed a larger hematoma in the ND group on the first postoperative day ( p = 0.02), but no significant difference was found by the fifth day. Conclusion: The use of drainage in TKA is associated with increased blood loss and transfusion rates without providing long-term clinical benefits. While it may offer temporary pain relief and reduce early hematoma formation, its routine application should be reconsidered given the potential for increased postoperative anemia and patient discomfort, along with the lack of sustained pain reduction. Surgeons should carefully weigh its short-term benefits against its risks, particularly in patients with pre-existing anemia or those at risk for significant blood loss.