Pistacia L. belongs to the family of Anacardiaceae. It contains nine species and five subspecies. P. vera L. (cultivated pistachio) is the economically most important species in the genus. It has edible seeds and considerable commercial importance. Iran, the United States, Turkey and Syria are the main pistachio producers in the world. Gaziantep province is the main producer and exporter of pistachio in Turkey. Samples of leaves, branches and fruits of pistachio (P. vera L.) were collected between 2009 and 2010 from different localities in Gaziantep province. Cytospora sarothamni Sacc., Phoma pulchella (Berk. and Broome) Sacc. and Steganosporium irregulare Lambotte and Fautrey are new records for Turkish mycobiota. For the first time in literature, Bispora antennata (Pers.) E.W. Mason, Coniothecium complanatum Nees (Sacc.) and Rosellinia pulveracea (Ehrh.) Fuckel were found on P. vera L., and P. vera L. is now defined as a new host plant for these three species.