| This research was carried out to investigate the length-weight relationship and condition factor of Coptodon guineensis from the New Calabar River and Buguma Creek, Nigeria. Assessments of the length and weight parameters indicated that the total length ranged from 12.4 cm to 29.8 cm with a mean value of 17.84±0.40 and the weight varied between 41g to 640g in subject collected from New Calabar River population. In Buguma Creek, the total length ranged from 10.9 cm to 23.5 cm with a mean value of 14.99 ± 0.26 and the weight was from 21g to 520g. The b value varied between 2.96, which were recorded for New Calabar River population, and 3.28 that was observed for Buguma Creek population. However, the condition factor of C. guineensis from Buguma Creek was significantly (p<0.005) higher than New Calabar River. These results demonstrate that the well-being of the species was slightly better in Buguma Creek than New Calabar River. Collectively these findings confirmed the ability of the species to thrive in brackish water and freshwater, and that these parameters support the assessment of the well-being of different fish in different locations.