Aim: This study aimed to characterize the neoplastic and cystic abdominal masses in children, reporting to the tertiary care center in Visakhapatnam. Objectives: The objectives include reporting on the age of presentation, sex distribution, incidence, history, presenting features, organs involved, investigations, resectability of tumor, operative procedures, post-operative status, and recurrence. Additionally for malignant swellings, the stages of presentation, adjuvant chemotherapy, or radiotherapy are reported. Materials and Methods: A longitudinal, prospective study was conducted from 2014 to 2017 in which 370 participants were recruited by consecutive systematic sampling. The children presenting with abdominal mass to the department of pediatric surgery, below the age of 13 were included in the study. Abdominal masses having acute presentations and hepatosplenomegalies due to medical causes were excluded from the study. Descriptive statistics were used to report on various stated objectives. Results: Wilm's tumor was the most common malignant tumor, and pelvic-ureteric junction (PUJ) obstruction was the most common benign condition causing abdominal mass. The other abdominal masses are reported in terms of stated objectives. Conclusion: Wilm's tumor was the most common malignant tumor. The incidence of advanced and metastatic tumors is considerably higher with tumors being reported at Stage 3 or Stage 4 in initial presentations. PUJ obstruction was the most common cause of benign renal masses, with half of the cases being detected antenatally and had improved renal function post-pyeloplasty. Masses involving the gastrointestinal tract and those proved benign in histology had a good prognosis. The prognosis of malignant tumors could only be commented by further studies with higher samples and strict follow-up. Clinical Significance: The abdominal swellings in children are reported when parents find a notable change in children. Awareness, education, and parental motivation may help in the early diagnosis of swellings that could be initial stages of fatal diseases. The importance of a child's age as a prognostic factor must be considered by the clinicians while planning surgical treatments.How to cite this article: Garikapatri NK, Dunna V, Konakyana H, Kolachana K. Characterization of neoplastic and cystic abdominal masses in children, reporting to the government tertiary care center in Vishakhapatnam -A longitudinal, prospective study.