HIV/AIDS is the single biggest threat emanating from the macro environment facing firms today. It has been estimated that 22.6% of the total population in the 20 to 65 year old age group is currently infected, and that this will rise to 26% by the year 2005 (ASSA2000 Model, Change Scenario). Firms need to track what is occurring, anticipate what may occur in the environment and take appropriate measures. Such environmental scanning should be an ongoing process. The purpose of this paper is to provide an overview of the impact of HIV/AIDS on the external market environment (uncontrollable factors)