Discoid lateral meniscus is a well-documented pathology, but symptomatic discoid lateral meniscus in a very young child and arthroscopic management are extremely rarely reported. We report a case of symptomatic discoid lateral meniscus in a 26-month-old girl who showed limping and extension loss after a minor trauma. Physical examination revealed clicking and 10 degrees terminal extension loss, which was suggestive of the torn discoid meniscus. Magnetic resonance imaging showed discoid lateral meniscus with intrameniscal tear. Treatment consisted of arthroscopic one-piece excision technique with conventional arthroscopic instrument and a No. 11 blade. A good subjective and objective functional outcome has been obtained after 35 months of follow-up evaluation.