Objective. Patients frequently present with knee complaints in general practice. Information about the course and prognosis of knee complaints is needed to inform patients and facilitate decisions on referral and treatment. The objective of the study was to assess the course of knee complaints and to identify predictors of outcome in patients visiting their general practitioner with a new episode of knee complaints. Methods. Data were collected by means of self-administered questionnaires. After 3 and 12 months of followup, the following outcomes were assessed: perceived recovery, change in pain, and change in physical functioning. As potential predictors of outcome, several sociodemographic variables, characteristics of the symptom, baseline scores of the outcome measures, and intra-and extra-individual variables were analyzed using multiple regression analyses. Results. We included 251 patients with a new episode of knee complaints presented in general practice. Only 25% reported recovery after 3 months, increasing to 44% after 12 months. A history of knee complaints, a longer duration of the current episode of knee complaints, other coexisting musculoskeletal complaints, and a higher level of distress were associated with a worse prognosis. In the linear regression models, 41-53% of the variance in pain reduction and improvement in functioning could be explained by the predictors. The area under the receiver operating characteristic curves, estimating the predictive accuracy of the Cox regression models concerning perceived recovery, was 0.77 after 3 months and 0.72 after 12 months. Conclusion. Many patients did not recover after 12 months. Distress was found to be strongly associated with less pain reduction and less improvement in functioning.