Background: Cervical lymphadenopathy is a common condition in pediatric patients, and early diagnosis is crucial for appropriate treatment. Fine Needle Aspiration Cytology (FNAC) is a valuable diagnostic tool. Objective: This study aimed to assess the accuracy and usefulness of FNAC in diagnosing pediatric cervical lymphadenopathy in patients under 12 years of age. Method: A prospective study was conducted at Sher-E-Bangla Medical College Hospital from November 2022 to February 2024. A total of 45 pediatric patients with cervical lymphadenopathy underwent FNAC followed by lymph node excision biopsy. FNAC results were compared with histopathological findings to evaluate the diagnostic accuracy. Results: Out of 45 patients, FNAC diagnosed 34 (75.55%) reactive hyperplasia, 2 (4.44%) tubercular granuloma, 1 (2.22%) non-tubercular granuloma, 2 (4.44%) pyogenic, 1 (2.22%) Hodgkin’s lymphoma, 3 (6.66%) non-Hodgkin’s lymphoma, 1 (2.22%) suspicious of malignancy, and 1 (2.22%) unsatisfactory for malignancy. The histopathological assessment confirmed 1 reactive lymph node as malignant (false negative), with no false positives. The sensitivity for benign conditions was 97.56%, specificity was 100%, positive predictive value was 100%, negative predictive value was 66.66%, and overall diagnostic accuracy was 97.67%. Conclusions: FNAC is a highly accurate and useful tool for diagnosing pediatric cervical lymphadenopathy and should be included in the initial diagnostic process before determining the treatment plan.