This study aims to determine the presence of sexual dimorphism based on morphometric characteristics in 69 (female: 44 male: 25) Syngnathus abaster specimens captured with seine-net from Lake Bafa's coasts (Mugla) between November 2014 and March 2016. Female/Male ratio of samples is 1/0.6. Based on morphometric measurements, the presence of sexual dimorphism was determined in among specimens pooled according to total length groups (I: 50-74 mm; II: 75-99 mm; III: 100-124 mm IV: 125 mm>). Thus, a statistical difference (p <0.05) is present between sexes in terms of body height (BH). Total length of males having a positive allometric growth is greater than that of female specimens, whereas females are higher than males. According to size groups, statistical sexual differences (p <0.05) were observed among length groups II and III of females and length group I of males. In conclusion, the species Syngnathus abaster, which is included in the Least Concern (LC) category of IUCN Red List, appears to have sexual dimorphism in the Lake Bafa's coasts in terms of body height.