Leaf warblers are one of the most challenging genera of birds to identify in the field, with 12 species reported from Iran so far. Considering the identification challenges, knowledge of their morphological characteristics and occurrence points have important implications for conservation and birdwatching. In this article, we are reporting an observation of a species of leaf warblers in Zahedan. Our investigation showed that the individual observed was a Dusky Warbler, which has only been reported once from Iran in the west of Gilan province. This warbler was identified from the images provided and national and international experts confirmed its identification. Since this species has not been reported from southeastern Iran and there is a lack of sufficient information about the distribution of this species in the country, this report is considered a new locality for the presence of this species in Iran as the first record of the species in Sistan and Baluchestan province and the second national record of the species.