Pediatric psoriasis accounts for nearly one-third of the global psoriasis burden. Multiple lines of evidence have shown the relationship between Angiotensin-converting enzyme (ACE) Insertion (I)/deletion(D) polymorphism with psoriasis susceptibility, and oxidative stress (OS) in psoriatic patients. However, such studies, particularly on pediatric psoriasis, are scarce in the local setting. Our study investigated the prevalence of ACE I/D polymorphism and its associations with oxidative stress in pediatric psoriasis patients in Sri Lanka. Thirty patients were recruited for this study after obtaining ethical clearance. The polymerase chain reaction was used to explore the ACE I/D polymorphism. Serum Nitric Oxide (NO) levels and the Total Antioxidant Capacity (TAC) were measured using the Griess assay and the FRAP assay. Clinical details were obtained from the clinic reports. Female predominance (76.67%) in pediatric psoriasis was reported, while Plaque psoriasis (66.67%) was found to be the most prevalent form. I/D was reported as the predominant genotype (66.67%) while I/I and D/D genotypes were recorded in 23.33% and 10% of patients, respectively. Significantly higher NO levels were observed in I/D patients than in I/I patients but not among other groups. No differences in TAC among ACE genotypes were reported. This pilot study revealed female gender and I/D genotype with increased NO levels as risk factors for pediatric psoriasis in Sri Lanka. However, it is prudent to increase the sample size to further validate the results.