Introduction: Adenovirus (ADV) infection is a life-threatening complication following hematopoietic stem cell transplantation (HSCT). Cidofovir is the primary therapy; however, its use is often limited by nephrotoxicity , and real-world data in pediatric cohorts remain scarce. Objective: This single-center retrospective study evaluated the efficacy and nephrotoxicity of cidofovir for ADV infection in pediatric HSCT recipients. Methods: We retrospectively analyzed pediatric HSCT recipients who received cidofovir for ADV infection at our center between January 2021 and December 2025. The primary outcome was virological response, defined as a ≥2 log₁₀ reduction in ADV DNA load from baseline. Results: A total of 23 pediatric HSCT recipients (17 males, 6 females) with a median age of 6.4 years (range, 1.0-16.4) were included. Primary diseases included acute leukemia (n=15), Wiskott- Aldrich syndrome (n=4), aplastic anemia (n=3), and Fanconi anemia (n=1). The median time from HSCT to ADV infection was 57 days (range, 3-370). Patients received a median of 3 doses of cidofovir (range, 1–5). Of the 23 patients treated with cidofovir, 19 had evaluable data on quantitative adenovirus DNA testing. Among these, 13 (68.4%) achieved a virological response, including 9 (47 .4%) who achieved complete viral clearance. Four patients lacked virological follow-up: 3 showed clinical improvement, 1 progressed. Over a median follow-up of 5 months, no grade ≥2 nephrotoxicity was observed. Conclusion: Cidofovir demonstrated a favorable safety profile with no significant nephrotoxicity when administered via a standardized short-course regimen. This therapy effectively reduced viral load and improved clinical outcomes in a subset of patients.