Alkaline proteases are commercially important group of enzymes and have a large variety of applications, mainly in the detergent, leather, and food industries. Most of the proteases currently used in the market are serine proteases produced by Bacillus strains. Fish viscera have wide biotechnological potential as a source of digestive proteases. Biotechnology provides a means for transforming such materials usually discarded into valuable produts such as enzymes. The objective of this research was to test if alkaline proteases from fish viscera could be used as an additive in commercially available detergent formulations. Viscera from Colossoma macropomum, the most important native fish for Brazilian aquaculture were extracted and used as a source of enzyme for this research. The crude extract obtained upon the homogenization of the viscera was submitted to a partial purification with ethanol. The protein content and proteolytic activity of the fractions obtained was assessed. The fraction presenting the highest proteolytic activity was further studied (30-70% of ethanol) resulting in 74.9% of protein recovery. This fraction was assayed at different temperatures and pH aiming to estimate the conditions for higher proteolysis. Temperarture and pH stability experiments were also carried out. Different commercially available detergents, surfactants and hydrogen peroxide were used to test the compatibility of these proteases with detergent formulations.  The results reveal that these alkaline proteases extracted from C. macropomum show desirable characteristics for its use in laundry industry such as: retention of 73% and 63% of its initial activity in the presence of Surf® and 5% H₂0₂, respectively, after 1 hour of incubation at 40ºC. In addition to that it was observed a slight increase of the proteolytic activity in the presence of non-ionic (Tween 20 and Tween 80) and ionic surfactants (Saponin and Sodium cholate).