This study aimed at evaluating the yield of mechanically separated meat (MSM) in natura and post-smoking obtained from the African catfish (Clarias gariepinus) slaughtered in different weight ranges (A: 0.214 to 0.402 kg; B: 0.538 to 0.634 kg; C: 0.780 to 1.000 kg; D: 1.132 to 1.314 kg; E: 1.396 to 1.706 kg). In a completely randomize design composed by five treatments and 16 replicates, 80 fish were used. The yields of clean trunk and its residues, MSM in natura, MSM wastes and smoked MSM were evaluated, as well as the physic-chemical composition of in natura and smoked MSM. Additionally, a test of acceptance of the byproduct of smoked MSM was performed. Data were submitted to a variance analysis followed a Tukey's test at a 5% significance level. Weight ranges did not differ (P < 0.05) in relation to the yields of clean trunk, MSM production and after the smoking process. From the physic-chemical analysis of the MSM in natura, the product was classified as semi-fat fish meat. The smoked MSM displayed an increase in protein, lipids and ash contents in comparison to the MSM in natura. The acceptance test did not show significant differences among weight ranges, displaying mean values that correspond to "like it slightly". Thus, it was concluded that C. gariepinus can be processed from a weight of 0.600 kg, the MSM in natura presented satisfactory organoleptic characteristics, and higher consumption frequency of smoked MSM is achieved when the fish weight 0.900 kg.