Lyme disease is the most common tick-borne disease in North America. Our review of the literature found few reports of Lyme disease presented in the orthopaedic literature. However, Lyme disease presenting as a popliteal cyst, with or without rupture, is rarely reported. We present 4 cases of Lyme disease that initially presented to our pediatric orthopaedic clinic for treatment of a popliteal cyst. The early diagnosis and treatment of Lyme disease may help prevent the often-devastating long-term sequelae of Lyme disease. The goal of this article is to increase the awareness of Lyme disease presenting in children as a popliteal cyst.