Abstract : This literature review explores the use of seashells as an alternative material for reinforcing concrete, focusing on their mechanical performance, environmental impact, and structural potential. Seashells, primarily composed of calcium carbonate, have been studied as partial replacements for fine and coarse aggregates or cement. Research shows that seashell-reinforced concrete can improve tensile and flexural strength, enhance durability, and contribute to sustainability—particularly when used in low-strength and non-structural applications. However, challenges such as reduced workability, early compressive strength loss, and variability in performance based on seashell type and treatment remain critical concerns. The review highlights the importance of factors including microstructure, pre-treatment methods, and optimal replacement ratios. It also identifies gaps in current research and suggests that collaborative, interdisciplinary studies are needed to optimize the application of seashells in modern construction. Overall, the integration of seashells into concrete mixes represents a promising avenue for sustainable development and environmental stewardship in the construction industry.