The reproductive characteristics of the Short-snouted Seahorse, Hippocampus hippocampus, was studied in the eastern Black Sea shore over a one-year period. Average standard length was 10.38 cm (6.15-13.3 cm) and weight 1.88 g (0.68-3.02 g). Males were slightly more common than females (females: 48%), but the difference was statistically insignificant (p>0.05). This was highest in autumn and lowest in winter, while there were no differences between the sexes (p>0.05). A sequential spiral of developing oocytes was observed from the earliest stage in the germinal ridge to the mature edge with the largest oocyte. Mature oocytes were found in histological sections during the summer season and the results obtained from gonadosomatic index values confirmed that the summer season is the breeding period of H. hippocampus at the eastern Black Sea shore of Turkey.