Citrus Huanglongbing, aka greening disease, has been the subject of several reviews in recent years. In this article, the author presents a concise compilation of the main features and symptoms of the disease, the causal organisms and the vectors including impacts for Florida and Brazil, two relatively new areas where the disease has been discovered, as well as implications for California, Texas, and Arizona citrus industries, which are threatened by the close proximity to the new Florida epidemic, and the rest of the western hemisphere. Accepted for publication 19 June 2007. Published 6 September 2007.