Biological aspects (length frequency distribution, length-weight ratio, sex ratio, allometric growth, Fulton?s condition factor) of Upogebia pusilla were studied in Tivat Saline (Tivatska solila), Boka Kotorska Bay in 2019. A total of 1,415 individuals were collected. The total length of all studied individuals ranged from 27 to 55 mm (8 and 20 mm CL), while the total weights ranged from 0.29 to 2.56 g (the total length of males ranged from 27 to 51 mm, non-ovigerous and ovigerous females ranged from 27 to 51 mm and 30 to 55 mm, respectively; the weights ranged from 0.29 to 2.52 g, 0.34 to 2.52 g and 0.47 to 2.56 g for males, non-ovigerous and ovoid females, respectively). The overall female:male ratio was 1.2:1. Ovigerous females were recorded from April (74.3%) to June (23.8%), with a peak in May (91.4% of all females). Males dominated in July (66.4%). The relationship between CL and W was negatively allometric in both males and females and in all sampled individuals. Fulton?s condition factor was higher only in females during the breeding season, while there were no significant differences between males and females during the rest of the year. Since this species is mainly used as live bait for commercial and sports fishermen, the results of this study would be useful for the sustainable management of this species.