Osteochondritis dissecans of the patella is a rare cause of anterior knee pain. An illustrative case in a 22-year-old man demonstrates the current imaging modalities and surgical treatment. Specifically, magnetic resonance imaging (MRI) and arthroscopic knee surgery are discussed along with a review of the literature. Unlike standard roentgenograms, MRI can be helpful in determining the viability of the osteochondritic fragment and the amount of remaining attachment to the surrounding cancellous bone. This finding can have important bearing on choice of treatment. When surgery is indicated, arthroscopic treatment with excision of the fragment and curettage offers distinct advantages over open arthrotomy. Lateral release or other realignment procedures may be done in combination with the primary procedure. Prognosis for full recovery of knee function and relief of patellar pain is guarded in patients who require surgery.