The near daily news reports on food-borne diseases caused by contaminated produce, dairy, or meats suggests to the public that the safety of the U.S. food supply is in jeopardy. These reports, as well as a general distrust in federal agencies due in part to mad cow disease and toxigenic forms of "E. coli" in ground beef, have resulted in an increasing demand for "organic" foods and an interest in sustainable agriculture (Macilwain, 2004). It is, therefore, timely and appropriate to provide classroom lectures and laboratory experiences to show that microbes are ubiquitous in the environment, including in the foods that we eat. In presenting such material, it is important that we distinguish between common microbes and potentially harmful pathogens. In particular, it is imperative to place an emphasis on the fact that many bacteria and fungi are both beneficial and necessary for crop production and robust ecosystems. This hands-on laboratory experience has the added benefit of reinforcing safe food storage and preparation. The lab described in this article was specifically adopted for an undergraduate course "Pathogens, the Environment, and Society" for the Bioenvironmental Sciences undergraduate degree program at Texas A&M University. This laboratory exercise uses simple microbiology techniques and can be completed in three one-hour sessions. The objective is to reveal the intimate relationships between plant pathogens and environmental and food safety issues in agriculture. (Contains 1 figure and 4 tables.)