Infected twig with superficial black mycelial growth of fungi were collected from Dhaka city during the period of April, 2008 to July, 2009 A-D. The experiment was carried out in the laboratory of Mycology and Plant Pathology, Department of Botany, University of Dhaka. Twenty samples were examined from infected leaves of Chatharanthus plants. The fungi were isolated on PDA (Potato Dextrose Agar) medium following “Tissue planting method” (Tuite 1969). Percentage association of the fungi was also recorded. Identification of the isolates were determined following the standard literatures (Ellis 1971,1976 and Ellis and Ellis 1997). Pathogenicity of the isolated fungi was done following detached leaf technique (Azad and Shamsi 2011). Present investigation revealed the presence of seven species of Dematiaceous Hyphomycetes associated with infected leaves. The isolated fungi were Alternaria alternata, Alternaria sp., Arthrinium saccharicola, Aspergillus flavus, Curvularia brachyspora, C. eragrostidis and Monilia sp. Frequency percentage of association of Alternaria spp. was higher (37.7) and A. saccharicola was lower (2.2). Alternaria alternata (Fr.) Keissler). Colony black to olivaceous-black on PDA medium. Mycelia brown, septate, branched. Conidiophores brown, short or elongate, 17 - 65 (76) µm long and 8 - 12 µm in width. Conidia obclavate, obpyriform, sometimes ovoid or ellipsoidal, often with a short conical or cylindrical beak, pale brown, smooth or verrucose, 3 - 5 transverse septate and 0 - 4 longitudinal or oblique septate, 30 - 67 (76 ) × 9 - 20 µm in the broadest part. Beak pale, 2, 4 - 5 µm thick. The genus contains 44 species of which most are plant parasites, but a few species are ubiquitous and are also frequently soil-borne. Alternaria alternata is the commonest of these. Although usually seen as saprophytic contaminants. Alternaria sp. Colony grayish black. Mycelia brown, septate, branched, partly superficial partly immersed. Conidiophores brown, short or elongate arising singly from hyphae, 12 - 68 µm long and 7 - 11 µm in width. Conidia obclavate, obpyriform, sometimes ovoid or ellipsoidal, often with a short conical or cylindrical beak, pale brown, smooth 52 - 83 (55) × 15 - 26 µm in the broadest part. Beck pale, 4 - 10 µm thick. Arthrinium saccharicola Stevenson. Colonies whitish with black spore mass, mycelia brown, septate, branched. Conidiophores short, brown. 2 - 4 µm, conidia, grown, sub circular to circular or ellipsoidal, smooth, sometimes with median slit, 7.1 - 9.4 µm. The fungus is mostly saprophytic, isolated from sugarcane. Mostly saprophytic in nature. Aspergillus flavus Link. Colony yellowish green, spreading rapidly on PDA medium. Conidiophores deep brown, arising from submerged hyphae, 450 to 970 µm long, 6-15 µm diameter. Vesicles 10 to 30 or 40 µm diameter. Primary sterigmata 7 - 10 × 3-4 µm, secondary sterigmata 7 - 10 × 2.5 - 3 µm. Conidia pale green, pyriform to almost globose, 3 - 4 × 4-5 µm. It is mostly saprotrophic but sometimes pathogenic fungus with a cosmopolitan distribution. It is best known for its colonisation of cereal grains and legumes. Post-harvest rot typically develops during harvest, storage, and/or transit.