We report the case of an 8-year-old boy with the phenotypic features of Coffin-Siris syndrome diffuse hypertrichosis, flat occiput, scant scalp hair, flat supraorbital arch, triangular eyebrows, horizontal palpebral fissure, anteverted nares, triangular philtrum, coarse lips, high-arched palate, micrognathia, low set and dorsaly rotated ears, short neck, wide thorax, widely set nipples, transverse palmar crease, psychomotor delay, urinary malformations (paraurethral diverticulum, hypoplasia of left kidney associated with vesicoureteral reflux grade 3-4), bilateral inguinal hernia, and dorsolumbar kyphoscoliosis. In the follow-up he presented a retroperitoneal neuroblastoma. Although this type of tumor has been referred to develop in several genetic and mutimalformative syndromes, it seems that present association has not been previously reported.