The effects of pH on the protein solubility, film-forming ability of lizardfish viscera (stomach and intestines) and physico-chemical properties of the biodegradable films were investigated. The new approach could successfully yield protein-based films from lizardfish viscera at a narrow pH range (2 - 4, and 13) without the need for a protein extraction process. All films were observed to completely block UV light transmission. Films at pH 13 were hydrophilic, exhibited the lowest mechanical strength, highest deformability, and greatest yellowish color, while films at pH 4 were mechanically stronger, slightly deformable and showed superior light transmission barrier properties compared to other film samples. The substantial contribution of disulfide bonds to the formation of the three-dimensional network of films at pH 4 was confirmed by SDS-PAGE. Thus, films from lizardfish viscera can be utilized as a renewable packaging material in food systems.