Large periapical lesions, regardless of whether they are granulomas, abscesses or cysts, are primarily caused by root canal infection. Thus the treatment protocol should be elimination of etiological factors in the root canal system rather than their product, apical true cyst. A 10 year old female patient reported to the Department of Pedodontics and Preventive Dentistry, Dr R Ahmed Dental College & Hospital, Kolkata, with the chief complaint of pain and swelling in relation to upper front fractured teeth. Clinical and radiological findings were suggestive of periapical radicular cyst. Non-surgical endodontic therapy was performed using 1% sodium hypochlorite solution irrigant and Calcium hydroxide intra canal medicament. A 12 months follow-up radiographic examination revealed progressive involution of periapical radiolucency without any clinical symptoms. Periapical cysts respond favorably to non-surgical endodontic treatment and should be considered as primary treatment modality. How to cite this article: Dandotikar D, Peddi R, Lakhani B, Lata K, Mathur A, Chowdary U K. Nonsurgical Management of a Periapical Cyst: A Case Report. J Int Oral Health 2013; 5(3):79-84.