Studies that aim to discover amphibian and reptilian species were conducted in the Istanbul islands which consists of Buyukada, Heybeliada, Burgazada and Kinaliada, during the years 2016-2019. The latest research of the islands was done 39 years ago and no studies were conducted since then. This study investigated the differences in species of amphibians and reptiles over these years. Bufotes variabilis (Pallas, 1769) from Buyukada, Hemidactylus turcicus (Linnaeus, 1758) from Heybeliada and Testudo graeca Linnaeus, 1758 from Kinaliada were given as new records from these localities. Principal components analysis (PCA) was applied to analysis the correlation of the amphibian and reptile diversity between Istanbul islands, Marmara islands and mainland. PC1 (eigenvalue of 1.91082) was accounted for 45.86 % of the variation. Results of PCA, Podarcis sloth's (Rafinesque & Schmaltz, 1810) was observed to display an extant and dominant population in all of the islands. Hierarchical Cluster Analysis was performed to assess the similarity in species among the islands. According to HCA, three cluster groups were formed. Islands of Istanbul have separate groups from other islands and mainland.