Systemic amyloidosis is a very rare complication of inflammatory bowel disease (IBD). The reported cases of secondary amyloidosis in children with IBD are much fewer than those reported in adults. Herein, a teenage boy with Crohn’s disease is presented who developed nephrotic syndrome due to renal involvement secondary to amyloidosis, whereas the patient was under treatment with corticosteroid and 6-mercaptopurine. To our best knowledge, this is the first reported case of secondary amyloidosis in a teenage Iranian boy with Crohn’s disease.