Petri disease or black goo is a serious disease of young and old vines in most areas where grapevines are cultivated. Wine and table grapes are important export commodoties. Yields have, however, been severely affected worldwide by Petri Disease. the disease complex is not well understood, but is attributed to a complex of Phialophora-like fungi. The disease is typically associated with grapevines exhibiting a slow dieback as well as stunted growth. An international forum (International Council on Grapevine Trunk diseases) was initiated and three international workshops have thus far been conducted where research pertaining to Petri Disease and other trunk diseases of grapevines were presented. Most of the Petri Disease organisms have also been isolated from humans with AIDS. This relationships between human and plant infections is not well understood. Several new species have been delineated from this disease complex, and described in the genera Phaeocremonium and Phaeomoniella. the objectives of this programme are to focus on Petri Disease and the interaction of the fungi associated with this disease, with the aim to obtain a better understanding of their genetic diversity, the occurrence of a sexual cycle, epidemiology, mode of infection, and to develop effective ways to facilitate early disease detection.