Objective. To evaluate the influence of age, sex, body mass index (BMI), extent of meniscal resection, cartilage status, and knee load on the development of radiographically evident osteoarthritis (OA) of the knee and knee symptoms after meniscal resection.Methods. We evaluated 317 patients with no cruciate ligament injury (mean ؎ SD age 54 ؎ 11 years) who had undergone meniscal resection 15-22 years earlier (followup rate 70%), with radiographic and clinical examination. The Knee injury and Osteoarthritis Outcome Score was used to quantify knee-related symptoms. Sixty-eight unoperated subjects identified from national population records were included as a reference group.Results. Symptomatic radiographic OA (corresponding to Kellgren/Lawrence grade >2) was present in 83 of 305 operated knees (27%) and 7 of 68 control knees (10%) (relative risk 2.6, 95% confidence interval [95% CI] 1.3-6.1). Patients who had undergone total meniscectomy and subjects with obesity (BMI >30) had a greater likelihood of tibiofemoral radiographic OA than those who had undergone partial meniscal resection and those with a BMI <25, respectively. Furthermore, degenerative meniscal tear, intraoperative cartilage changes, and lateral meniscectomy were associated with radiographic OA more frequently than were longitudinal tear, absence of cartilage changes, and medial meniscectomy, respectively. Symptomatic tibiofemoral or patellofemoral radiographic OA was associated with obesity, female sex, and degenerative meniscal tear.Conclusion. Contributing risk factors for OA development after meniscal resection are similar to risk factors for common knee OA. Systemic factors and local biomechanical factors interact. Obesity, female sex, and preexisting early-stage OA are features associated with poor self-reported and radiographic outcome. Partial meniscal resection is associated with less radiographic OA over time than is total meniscectomy.