Pesticide use reporting systems are becoming more widespread. The data gathered by these systems has enormous potential for a wide range of applied research. Arizona's pesticide use reporting system illustrates both the opportunities and pitfalls that will arise with the increased use of reporting systems. The data available provides a detailed and extensive picture of pesticide use in major Arizona crops like cotton. With improvements it could be the cornerstone of research that benefits producers and the environment. As it stands, however, the Arizona pesticide reporting system lacks fundamental information essential to make it a useful data source. Summaries illustrate both the strengths and weaknesses of the Arizona reporting system. Preliminary research results provide an example of the potential power of the dataset.