The processed citrus industries of Sao Paulo, Brazil and Florida, United States collectively account for over 80 percent of world orange juice production. In recent years, both industries have been confronted with serious plant disease outbreaks. Porter’s Diamond framework is used to assess the strengths and weakness of the processed citrus industry in each country to confront the combined challenge of effectively combating these diseases while maintaining market competitiveness. Although Sao Paulo and Florida produce a similar product, the Porter’s Diamond framework reveals that there are significant differences in the organizational structure of the two industries. The article concludes with an analysis of how these differences will impact each industry’s ability to sustain its global leadership in the international processed citrus market.