Many types of meniscal anomalies were reported. Authors found a double-layered lateral meniscus, with one meniscus overlying another. The 39-year old male patient had torn medial and lateral menisci. We performed partial medial and lateral meniscectomy, and incidentally found that lateral meniscus was double-layered. It was characteristic that the upper small accessory meniscus was firmly connected from the posterior horn to middle segments of the lower main meniscus along its peripheral edge. We left it alone. The symptoms were gone, So, it was thought that this anomaly was not related to the patient's symptoms.