Trials were established at Aula Dei Experimental Station (EEAD-CSIC, Zaragoza, Spain) to assess graft compatibility between peach cultivars [Prunus persica (L.) Batsch] and new Prunus spp. rootstocks or selections. Peach cvs. `Catherina' and `Tebana' and nectarine cvs. `Big Top' and `Summergrand' were grafted on peach seedlings, plum rootstocks, almond × peach hybrids, and other interspecific rootstocks. Part of the evaluated material belongs to the EEAD-CSIC selection program, which has showed good adaptation to Mediterranean growing conditions. Other rootstocks such as Bruce, Evrica, Hiawatha, Ishtara, Tetra, and Krymsk-1 have been recently introduced in Spain. A peach and a plum source, GF 677 and Adesoto 101, respectively, were used as compatible reference rootstocks. Both are widely used for peach and nectarine production in the Mediterranean area.