Juan Méndez obtained his BSc (1990) and PhD in Biochemistry and Molecular Biology (1995) from the Universidad Autónoma de Madrid (UAM). As a graduate student he worked with M. Salas at the Centro de Biología Molecular "Severo Ochoa". His PhD Thesis on bacteriophage DNA replication received First Class Honours from the Universidad Autónoma de Madrid, the Premio Juan Abelló from the Real Academia de Doctores and the Glaxo Wellcome Prize for Biomedical Research.
From 1997-2004 he was a Postdoctoral Fellow at B. Stillman’s Group, Cold Spring Harbor Laboratory, New York (USA). During this tenure he was supported by the Fundación Ramón Areces, Human Frontiers Science Program Organization and the US Department of Defense (Breast Cancer Programme) and studied the functions of human DNA replication proteins ORC, Cdc6 and MCM, as well as the impact of cyclin E deregulation in the DNA replication process in cancer cells.
In October 2004 he was awarded a Research Contract from the Ramón y Cajal Programme and appointed as Junior Group Leader in the CNIO´s Molecular Oncology Programme.