Lectins exhibit antiviral and antimicrobial activities by binding to glycans of pathogenic species. However, their therapeutic application is impeded by high manufacturing costs, low chemical stability, hemagglutination, cytotoxicity, and the potential risk of initiating an unfavorable immune response. These disadvantages have stimulated considerable efforts to develop small molecules with carbohydrate-binding properties (lectin mimics) that are readily preparable, chemically stable, and easily tunable, as alternatives to lectins. This review outlines the representative design concepts and carbohydrate-binding properties of lectin mimics and discusses their therapeutic potential in the treatment of infectious diseases. In addition to synthetic lectin mimics, naturally occurring lectin mimics, pradimicins, are also highlighted, and the molecular basis of carbohydrate recognition and their therapeutic potential are presented.