Abstract: Biological control agents Trichoderma koningiopsis Th003 and T. asperellum Th034have shown high efficacy controlling potato damping-off disease. Both isolates were formulatedas water-dispersible powder (WP) and water-dispersible granule (WG) containing 1×1010 and1x109 conidia.g-1, respectively. Aqueous suspension of these biopesticides [1×106 conidia ml-1]was applied to potato seedlings in pot trials under greenhouse conditions in order to evaluatebiocontrol against Rhizoctonia solani and plant-growth-promoting effects. Application of Th003WP and WG and Th034 WP resulted in 88 to 100% disease reduction. WG Th034 formulationshowed the lowest efficacy (54%) of disease control. The effect of Trichoderma spp. on biomassaccumulation, root and aerial part length, was not significant.