© 2019, ALÖKI Kft., Budapest, Hungary.Invasive non-native parakeet populations are increasing throughout Europe with proved negative impact on native fauna and Turkey is no exception. Rose-ringed and Alexandrine parakeets have established populations in Turkey’s large cities but even basic distribution, abundance and breeding behaviour information is missing. This study aims at determining the breeding status and identifying the nest characteristics of Rose-ringed and Alexandrine parakeets in Istanbul’s city parks. The study is carried out in 9 city parks during one breeding season. Data on the presence of breeding parakeet species, their nest characteristics and characteristic of suitable cavities on non-nesting trees were collected. Both species were recorded breeding sympatrically in 5 out of 9 city parks with probable breeding in one more park. When nesting, both species preferred high trees with high diameter but Rose-ringed parakeet nests were placed lower than those of Alexandrine parakeet’s. Plane (Platanus sp.) species were the most used as a nesting tree for both species. This study reveals the first systematic observations on the breeding Rose-ringed and Alexandrine parakeet populations in Istanbul and serves as a basis for further detailed research on both species in Turkey.