Purpose: The purpose of this study was to evaluate the impact of body mass index (BMI) on early functional results of patients who undergo isolated partial meniscectomy. Methods: The functional results for 1,090 patients who underwent partial meniscectomy, in 2 different orthopaedic clinics, were evaluated retrospectively. The study includes cases with arthroscopic partial meniscectomy for isolated meniscal tears; patients with concomitant knee pathology were excluded. Three hundred forty-one (31%) patients with isolated lateral meniscal tears, 628 (58%) patients with isolated medial meniscal tears, and 121 (11%) patients with both medial and lateral meniscal tears underwent arthroscopic partial meniscectomy. We divided these patients into 3 subgroups on the basis of their BMI; <26, between 26 and 30, >= 30. Preoperative functional results were compared with 1-year postoperative follow-up results using the International Knee Documentation Committee (IKDC),(26) Lysholm Knee Scale,(27) and Oxford Scoring System(28) scores. Results: According to all 3 knee scales, age, side of lesion, and tear type had no effect on functional outcome. When compared with the group with BMI <26, the patients with BMI between 26 and 30 and the patients with BMI >= 30 had significantly worse outcomes as measured by the IKDC, Oxford Scoring System, and Lysholm Knee Scale scores. Patients with BMI between 26 and 30 and >= 30 did not have significantly different functional outcomes. Conclusions: Short-term outcomes after arthroscopic partial menisectomy reflect significant improvement in subjective outcome. However, patients with moderate or significant obesity (BMI>26) have inferior short-term outcomes compared with nonobese patients. Level of Evidence: Level IV, therapeutic case series.