The objective of the present study is to assess and describe variation in the morphometric characters of Hippocampus guttulatus from various coastal locations of Turkey in the southwestern Black Sea. In total, 14 morphometric characteristics were examined in 210 specimens (115 females and 95 males). Mean length and weight were 11.89 +/- 7.73 cm and 1.54 +/- 0.41 g for females, and 12.24 +/- 8.13 cm and 1.60 +/- 0.42 g for males. Females and males were found to differ in the SL, TrL, TD4, LD and HD (P < 0.05). Males reached a greater length than females. The length-weight relationships were highly significant (P < 0.001). The estimated length-weight relationship for both sexes was W = 0.0027 x SL2.545(R-2 = 0.397). This relationship was W = 0.0018 x SL2.719(R-2 = 0.387) for females and W = 0.0034 x SL2.451 (R-2 = 0.416) for males.