This study assesses the length-weight relationships and the condition factor of Sarotherodon galilaeus in Bontanga reservoir in Tropical region, Ghana. Using W = aLb, the length-weight relationships of the species were calculated and condition factors of the species were obtained using the formula: W 100/L3. This study in length weight and condition factor of S. galilaeus in Bontanga reservoir, as well as physiochemical parameters of the reservoir, showed the regression coefficient (b) for S. galilaeus was 3.02846 at a confidence interval of 2.968648 - 3.088279 with Standard error 0.03039 of b at 5% Confidence limit and condition factor of (4.53- 5.03). The average temperature was 27.33oC, DO 6.34mg/l, turbidity was 45.88NTU, transparency 76.88cm and Conductivity was 71.49µS/cm. Thus all the observed physicochemical parameters were found to be within the optimum range for the growth of S. galilaeus. However, the study revealed that the gears and methods used in fishing in the reseviour do not allow fishes to grow to their maximum sizes. Hence argues for enforcement of good fishing practices.