A study was conducted in the Microbiology Laboratory of Plant Pathology Department, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, during 2005 to 2006 to control Colletotrichum dematium causing anthracnose of soybean with fungicides, plant extracts and Trichoderma harzianum. Five fungicides namely Tilt-250 EC, Vitavax-200, Rovral 50 WP, Dithane M-45 and Cupravit were evaluated at 100, 200 and 400 ppm for their efficacy against the radial colony growth and mycelial dry weight of C. dematium. The complete inhibition was obtained with Tilt-250 EC at all the selected concentrations. The highest concentration of Vitavax-200 inhibits 77.41% and 83.45% radial growth and mycelial dry weight, respectively and significantly superior to Rovral 50 WP at the highest concentration. Dithane M-45 and Cupravit were found to be significantly inferior against the test pathogen. Plant extracts of garlic, ginger, onion and neem at three different concentrations (5%, 10% and 20%) were evaluated against the radial growth and mycelial dry weight of C. dematium. Among the four plant extracts, garlic extract at 20% concentration was appeared to be best in inhibiting the radial growth and mycelial dry weight of the test pathogen followed by onion, ginger and neem extracts and each extracts were significantly different from each other. A total of 20 T. harzianum isolates collected from rhizosphere and rhizoplane of different crops were screened against C. dematium following dual plate culture technique. The screened isolates of Trichoderma showed significantly variable antagonism ranging from 50.93 to 89.44% reduction of the radial growth of C. dematium. Among the promising antagonists, the isolate T3 of T. harzinum showed the highest 89.44% inhibition of radial growth of C. dematium.