The 2004 World Health Organization classification includes the new entity "neuroblastoma-associated renal cell carcinoma." The pathogenetic link between these entities is unknown as yet. The patient reported herein developed renal cell carcinoma after anaplastic embryonal rhabdomyosarcoma, a previously unknown association. The 2nd malignancy developed very soon after the 1st one, prompting concern for inherent cancer predisposition rather than a therapy-induced 2nd malignancy. A variety of features raised suspicion for Tp53 mutation, and indeed a pathogenic germline Tp53 mutation was identified in this child, despite a negative family history for Li-Fraumeni syndrome. Consideration of underlying predisposition is advocated in the context of rapid evolution of 2nd childhood malignancy.