 His first wife was Urraca Fróilaz, daughter of Froila Arias and Ardio Díaz.They were married sometime before 12 August 1088, although a document surviving only in an eighteenth-century copy records their marriage on 11 August 1102.By 6 May 1105 Pedro had remarried to Mayor (Guntroda) Rodríguez (de Bárcena), daughter of Rodrigo Muñoz.