Chromolaena odorata, originating from South and Central America, is a bushy shrub invasive in many tropical and subtropical regions of the world. Several species of Mycosphaerellaceae have been reported on C. odorata in recent years as potential biological control agents. As a result, several exploratory trips were undertaken to south, north and Central America from 1988 until 1997 to survey for pathogens on C. odorata. Three new species of Passalora, and one species of Septoria and Pseudocercospora, respectively, are newly described. Furthermore, Septoria ekmaniana and Passalora perfoliati were also confirmed from Chromolaena during the course of this study.