Discoid meniscus of the knee is a well-known anatomic and congenital variant of the lateral meniscus. It is often asymptomatic, but can be associated with knee pain and other symptoms. Posterior dislocation of the discoid meniscus is an extremely rare finding; to the best of our knowledge, only one case has been reported in the literature. Here, we report a case of 10-year-old girl who presented with right knee pain with no history of trauma. The radiograph of her right knee was negative but MRI showed bilateral lateral discoid menisci with posterior dislocation in the right knee and some subluxation in the left. She underwent right knee arthroscopic lateral meniscoplasty with excellent outcome. This case demonstrates the possibility of torn and dislocated discoid lateral menisci management through arthroscopic reduction and repair.