Congenital insensitivity to pain with anhidrosis is an autosomal recessive disorder caused by mutations in the neurotrophic tyrosine receptor kinase 1 (NTRK1) gene, which encodes the receptor for nerve growth factor. We report the clinical and radiological pitfalls in the diagnosis and treatment of two brothers, aged 5 and 8 years, with congenital insensitivity to pain with anhidrosis, the older brother having a proven NTRK1 mutation. In the neonatal period, both presented with recurrent episodes of fever of unknown origin, but their clinical problems changed later. In addition to severe mental retardation and self-harming behaviour, the older brother developed recurrent nonbacterial destructive infections of both the calcaneus and later the talus. No immunodeficiency was found. The younger brother had three complex fractures with a long history of healing problems: overwhelming production of callus, osteomyelitis and movement restrictions. He has less mental retardation than his older brother and shows no self-mutilation.