Osteoarthritis (OA) of the knee, one of the most common causes of disability, continues to increase in prevalence as the older adult and obese populations grow. Often, the general practitioner is the first to evaluate a patient with a painful knee that has arthritis. Evidence-based evaluation and treatment guidelines recommend the use of nonoperative treatments before surgical treatment options such as total knee arthroplasty (TKA) are considered. Understanding available nonoperative treatment options is critical for physicians who first encounter patients with OA of the knee. The authors provide an overview of nonoperative treatment options for patients with OA, including weight loss, aerobic exercise, osteopathic manipulative treatment, nonsteroidal anti-inflammatory drugs, and corticosteroid injections. The authors also discuss operative treatment options to be considered before TKA and review indications for TKA when other treatment options have been exhausted.