After filleting and processing catfish, the waste generated can reach up to 50%, which could be further processed and generate additional revenue for the catfish industry . Acid silage is a potential low-cost and straightforward technology that can be applied to the catfish remains and be sold as a feed ingredient or supplement . In this study, t he acid silage was applied to catfish viscera, frames, and a composite sample of catfish remains ( whole-waste; heads, viscera, and frames) . The samples were incubated for 7 days, using two concentrations of hydrochloric acid - HCl (5 and 7%), as a promoter for acid hydrolysis to each waste source using three replicates. The silages were homogenized daily, and pH and temperature were assessed on days 3, 5, and 7. After seven days of incubation, the emulsifying stability and foaming capacity were measured. Data was analyzed as a 3 × 2 factorial with the waste source and acid levels as the main factors. Silages incubated with 7% HCL showed higher values for the variables analyzed (Table 1). The waste sources affected the pH , and a higher pH value was observed for the whole-waste silage. A higher foaming capacity was observed for the silage manufactured with f rames, possibly due to the higher muscle content in this residue. Catfish waste was amenable to acid silage , and additional processing methods (enzymatic and microbial) are being currently tested.