Altennria helianthificiens Simm., Wal. and Rob. was first determined in Yugoslavia in 1987, in the vicinity of Novi Sad and later on other locations. Disease symploms are manifested on sunflower leaf, stem and head. in the form of brown-red angular spots. In pure culture on PDA\ the fungus produces septated hyphae and multicellular condiophores with conidia.- Tle dimensions of conidia are 13.88-114.57 x 1.3g-11.0g *m (59.47-3.19 *m).- Tèmperatures between 0 antr 5ºC are minimum for [ungus developmenr, maximum ones are between 35 and 40ºC, whilc the and optimum is arouitl 15ºC. The temperatures 15, 20 and 30ºC are minimum, optimum and maximum, respectively, for fructification. The best mcdia for the development of mycelia were bean and cârrot media and carrot and prune media were best for conidia prduction. After two or three sowings on nutrient media, the fungus loses its ability of fructification (production of conidia). The incubation in greenhouse lasts for two dâys and after 10 days all plânts are dry. In field,l. helianthirtf;cierc was more pathogenic than A. helianthi but iess pathogenic than Phomopsis helianthi.-A. helianthinficiens overwinters in the form of mycelia on infected harvest residues and infected seeds, which are the maior sources of infection.