Waterborne epoxy coatings have attracted considerable interest as eco-friendly substitutes for conventional solvent-based coatings. However, their performance and durability frequently fail to meet the standards set by their solvent-based competitors. Using polyaniline (PANI) as an additive in aqueous epoxy coatings has become a potential method to improve their characteristics and broaden their uses. This chapter focuses on synthesizing, characterizing, and applying polyaniline-modified waterborne epoxy coatings. The chapter begins with an introduction to waterborne epoxy coatings, highlighting their advantages, limitations, and the need for performance enhancement. The synthesis and modification of polyaniline, including its various forms (e.g., emeraldine base, emeraldine salt) and functionalization techniques, are discussed in detail. The incorporation of polyaniline into waterborne epoxy coatings is explored through different methods, such as in-situ polymerization, solution blending, and surface modification. The effects of polyaniline content, dispersion, and interfacial interactions on the properties of the modified coatings are systematically investigated. The insights gained from this chapter contribute to the development of advanced waterborne coatings with improved performance and functionality, promoting their wider adoption in various industries.