Many clinicians are utilizing a 2-g loading dose of sulfisoxazole in the treatment of uncomplicated urinary tract infection. Although some of these clinicians understand the theoretical reasons for not utilizing such a treatment plan, they may be reluctant to depart from the official recommendations for sulfisoxazole because of the lack of supporting clinical data. The findings of this study provide support for the theoretical considerations outlined previously. Also, considering the potential disadvantages of the loading dose employment, for example, source of patient misunderstanding and complicated patient instructions data supporting the omission of a sulfisoxazole loading dose should be most welcome. In conclusion, the study results suggest that the inclusion of a 2-g loading dose of sulfisoxazole in the treatment of this sample of acute, uncomplicated urinary tract infections did not offer any therapeutic benefit.