Abstract: Background and Objective: The West African Lung Fish are common to the waters of West Africa. It is the only species in the genus Protopterus of the family Protopteridae found in the West African Swamps, studies have shown that the distribution and abundance of P. annectens are often affected by the construction of dams causing shift in salinity, flood, a significant rise in pollution. Investigation into the morphometric characteristics of P. annectens may provide steps into understanding the phylogeny, growth pattern and morphometric features responsible for survival of this economically important fish species in Nigeria. Materials and Methods: Ten morphometric and meristic characteristics of West African lung fish Protopterus annectens collected from river Niger at Agenebode between the periods of November, 2016 to October, 2017 using different fishing gears were analyzed. Out of the 345 specimens collected, 45 were analyzed to obtain the desired characteristics using graduated ruler and a digital scale. Results: The body weight and total length of fish ranged from 27.48-4230 g and 12.00-86.70, cm respectively. Negative allometric growth (b<3) was obtained for length-weight relationship with growth values of 0.12 and 0.34 for males and females, respectively. The relationships between the meristic and morphometric parameters measured for P. annectens were linear. Strong positive correlations (0.70; 0.88) were obtained between pelvic fin, pectoral fin and total length. The relationship between the head length and head width was positive where, b = 1.95 and the correlation coefficient was r = 0.73, positive correlations were also obtained for total length-pelvic fin with b = 3.17 and r = 0.70 and the relationship between the mouth gape and head length was also positive where, b= 0.86 and r = 0.66. Conclusion: River Niger is a good breeding ground for this fish species. P. annectens exhibits negative allometric growth pattern although P. annectens is not faring well in this water body. The morphometric parameters measured for P. annectens revealed that linear growth rates is obtained for P. annectens. The differences in parameters obtained for weight and length showed that P. annectens exhibits sexual dimorphism and also that the weight of fish is the most important component in the proper growth and well being of fish.