Background <p>Pediatric Castleman disease (CD) is a rare lymph node disorder, and renal involvement is uncommon in pediatric CD. This study aimed to investigate the clinical features of pediatric CD with renal involvement.</p> Methods <p>Clinical data from Beijing Children’s Hospital for pediatric patients with CD were analyzed retrospectively. All included cases were confirmed by lymph node biopsy, with one patient also undergoing renal biopsy.</p> Results <p>A total of 42 pediatric patients with CD were included, of whom 20 (47.6%) presented with renal involvement, with a median age of 10.9&#xa0;years. Renal manifestations included proteinuria (11 cases), acute nephritis (4 cases), nephrotic syndrome (2 cases), and acute renal failure (3 cases). Renal involvement generally coincided with CD onset and improved following etiological treatment of CD. One patient who underwent renal biopsy was diagnosed with minimal change disease. Notably, isolated nephrotic syndrome could occur during the remission phase of CD, presenting as steroid-resistant disease that responded to the addition of immunosuppressive agents.</p> Conclusions <p>Pediatric CD with renal involvement included proteinuria, nephrotic syndrome, acute nephritis, and acute renal failure. Renal involvement occurred simultaneously with CD and improved rapidly in all patients after etiological treatment of CD and immunosuppressants.</p> Graphical abstract <p></p>