Sulfonamides and their different derivatives are extensively used in therapy due to their pharmacological properties. Sulfa drugs were amongst the oldest synthesized antimicrobial agents and are still widely used today to treat different microbial infections. Clinical treatment with sulfonamides has regained confidence with the use of a combination of sulfamethoxazole and trimethoprim to treat urinary tract bacterial infections. Today, they are widely used as antimicrobial agents, chiefly because of their low cost, low toxicity and excellent activity against bacterial diseases. Over the course of time, the application of sulfonamides has been extended from their use as antimicrobial agents to anticancer agents, antiglaucoma agents, inhibitors of gamma-secretase, cyclooxgenase-2 and lipoxygenase, anticonvulsivant agents, hypoglycemic agents.