Genetic structure and some bio-ecological characteristics of lessepsian lizardfish Saurida lessepsianus populations collected from the Iskenderun, Mersin, and Antalya Bays were revealed by mtDNA sequencing of Cyt b dataset and length-weight relationships and the parameters of von Bertalanffy growth function. The highest genetic divergence was detected between the Mersin and Antalya populations (0.0026), whereas the lowest was between the Iskenderun and Antalya populations (0.0014). The length-weight relationships for all individuals of Iskenderun, Mersin, and Antalya populations were calculated as W = 0.0042 x L3.2207, W = 0.0039 x L3.1627 and W = 0.0196 x L2.6515, respectively. The von Bertalanffy growth parameters (L∞, k, and to) were estimated for all individuals as L∞ = 47.33 cm, k = 0.024, and to = -1.28 for Iskenderun; L∞ = 41.74 cm, k = 0.085 and to = -1.72 for Mersin and L∞ = 50.99 cm, k = 0.154 and to = -2.41 for Antalya. This study examines the genetic structure and bio-ecological characteristics of the S. lessepsianus populations on the Mediterranean coast of Türkiye together for the first time. Genetic findings and bio-ecological parameters of populations generally support each other and can provide support for future studies.