Giardiasis is a protozoal disease infecting 200 million people throughout the world. Giardiasis is widespread primarily in developing countries. Infections are correlated with poor hygienic conditions, poor water quality control, and overcrowding. There are very few therapeutics currently available, and drug development to treat giardiasis is hampered mainly by socioeconomic obstacles. This article presents the history of antigiardial chemotherapy and current state of therapeutic availability along with the future prospectus of development of antigiardial agents. In addition to accumulated knowledge about the previous and current antigiardial drugs, advanced technologies including computer-aided drug design and combinatorial synthetic chemistry, as well as high throughput screening techniques, accelerate understanding of the disease and further research toward a suitable antigiardial agent.