Abstract: This study was carried out on Auchenoglanis occidentalis (Cuvier and Valenciennes) from River Rima, North-Western Nigeria to provide information on morphometric relationships and relative condition factor. A total of 800 samples of A. occidentalis of which 398 were females and 399 males (giving a ratio of about 1:1) were examined between November 2005 and December 2008. Biometric data such as Total Length (TL) and Total Weight (TW) measurements were recorded in the laboratory. The samples ranged in total length from 6.60-33.00 cm with a mean of 19.51±4.50 SD and from 2.26-462.90 g total weight with a mean of 100.05±70.09 SD. For the length-length relationships, the b values were 0.814 for TL-SL; 0.242 for TL-HL; 0.200 for GTH-TL and 0.779 for HL-GTH, suggesting negative allometry or faster increase in Total Length (TL) than in all the other length parameters. The species exhibited isometric growth pattern in the overall samples (b = 3.023), females (3.001), males (3.002), dry season samples (2.969) and those ≥15 cm (3.030). Samples <15 cm exhibited negative allometry (2.851) while those caught during rainy season exhibited positive allometry (b = 3.113). The species were found to be in good condition with an overall Kn value of 2.27±0.08 SD in females and 2.26±0.08 SD in males in the river. In both sexes, samples ≥15 cm were in significantly (p<0.05) in better condition than those <15 cm and likewise, samples in the rainy season had higher (p<0.05) Kn values than those in the dry season. Based on gonad maturation stages, samples in the mature, ripe and running, spent and resting stages were in significantly (p<0.05) better condition than those in the maturing and immature stages.