Introduction: Adenoids together with palatine tonsils tubal tonsils and lingual tonsil form the inner Waldeyer's ring and its enlargement depends on external factors such as allergy, immunosuppression, passive tobacco smoke but mainly chronic bacterial and viral infection. The study compares the effectiveness of certain factors in conventional curettage versus endoscopic adenoidectomy in a tertiary care centre in Trivandrum, Kerala, India. Study was done with the objectives to study the perioperative collateral injury, presence of residual adenoid tissue and recovery time in conventional versus microdebrider assisted endoscopic adenoidectomy in children less than or equal to 12 years. Material and methods: An observational study was done in a group of 60 patients of age less than or equal to 12 years who satisfied the inclusion criteria who underwent treatment in department of ENT in Sree Gokulam medical college during a period of 2017-2018. Patients were grouped into 2 groups of 30 each. Group A underwent conventional curettage and group B underwent microdebrider assisted endoscopic adenoidectomy. Patients were followed up 1 week and 2 months following the procedure by post operative nasal endoscopy to assess collateral damage and residual adenoid tissue. Results: The residual tissue in conventional adenoidectomy was 20% and 20-50% in 2 cases and more than 50% in 4 cases. This was the main cause of persistence of symptoms in conventional adenoidectomy. The mean recovery time was 4.1 days in conventional and 3.2 days in endoscopic adenoidectomy. In conventional adenoidectomy 3 cases (10%) had collateral damage in which 2 cases had injury to eustacian tube orifice and 1 case had injury to torus tubaris. In the endoscopic microdebrider assisted surgery no collateral damage was recorded. Conclusion: The study showed that the completeness of dissection, collateral injury and recovery time was better in the endoscopic adenoidectomy compared to conventional curettage.