Abstract Soy protein is widely used as an additive in meat products. Brazilian legislation allows a maximum of 7.5% (dry wt) of textured soy protein in hamburgers; however, there is no reliable local methodology to quantify soy protein in meat products. The objective of this work was to investigate and apply indirect ELISA as a method for determining soy protein in hamburgers prepared from beef, chicken and swine meat. The 7S fraction was used to prepare the polyclonal antibody. A relative high incidence of soy protein was observed in this study: of 39 samples analyzed, 30.8% were found to exceed the legal specification. Indirect ELISA proved to be a simple, rapid and adequate method for quantifying textured soy protein in hamburgers, and should be considered a potentially valuable technique for inspection of foods containing soy protein.