Aim: To evaluate the thrombocytosis in Pediatric Patients with clinical and hematological characteristics at a tertiary care center in north India. Materials and Methods: The study included all children between the ages of 0 -16 who were attending pediatrics and pediatric super specialty clinics, both in outpatient and inpatient settings. The parameters of complete blood counts, including hemoglobin, red cell indices, and platelet indices PDW, MPV, and P‑LCR, were observed. Additional biochemical parameters, including C-reactive protein, erythrocyte sedimentation rate, serum iron profile, blood culture, and urine culture, were documented in accordance with the clinical indications for each individual case. Results: It was observed that the largest proportion of participants fell within the 0-4 years age group, accounting for 45% of the total sample. It was observed that 72.5% of the children exhibited mild thrombocytosis, while moderate and severe thrombocytosis were observed in 20.83% and 6.67% of the children, respectively. The etiology was found to be secondary or reactive in 98.33% of cases, with only two cases of primary thrombocytosis observed. Two cases of Philadelphia positive pediatric chronic myeloid leukemia (CML) exhibited primary or clonal thrombocytosis. The primary etiology of secondary thrombocytosis was found to be infection, accounting for 41.67% of cases. Among these cases, respiratory tract infections were responsible for the highest proportion, specifically 19.17%. The prevalence of iron deficiency anemia (IDA) was observed to be 12.5%, while the occurrence of IDA in conjunction with concurrent infection was found to be 10.83%. A prevalence rate of 9.17% was observed for hemoglobinopathies that were accompanied by secondary thrombocytosis. The second largest group consisted of cases of drug-induced thrombocytosis, accounting for 13.33% of the total. A notable observation in this study was the inverse relationship between platelet counts and mean platelet volume (MPV), as evidenced by the significant negative correlation (P<0.05) reported. Conclusion: The occurrence of thrombocytosis in pediatric patients is primarily attributed to secondary causes, while primary thrombocytosis, specifically clonal thrombocytosis, is exceedingly uncommon in this population. In children, infections are the primary cause of secondary thrombocytosis, which is typically a temporary condition and does not have significant clinical consequences.