Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 58 2 2020 06 29 94 96 Ehsan Valavi Department of Pediatric Nephrology, Chronic Renal Failure Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran Azar Nickavar Department of Pediatric Nephrology, Iran University of Medical Sciences, Tehran, Iran. Pouria Sharififard Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran. 2019 09 06 2020 04 23 This is the presentation of a 19-month-old female admitted for recurrent lower urinary tract infection. Renal ultrasound and computed tomography showed a round bladder stone with no associated abnormality. Open cystolithotomy was performed, and a large bladder stone, measured 3.2 x 2 x 3.2 cm, and composed of magnesium ammonium phosphate (struvite) was removed. To the best of our research, this is the youngest patient, involved with a large struvite bladder stone. https://acta.tums.ac.ir/index.php/acta/article/view/8067 https://acta.tums.ac.ir/index.php/acta/article/download/8067/5376