Two field trials were carried out at the Teaching and Research Farm of the University of Ilorin in the 2012 and 2014 planting seasons to find out the effeciency of Trichoderma harzianum as a bio-control agent in controlling root-knot nematode (Meloidogyne incognita) in two pepper varieties (F1 Nikita and Gianfranco Fuscello). A 2 × 2 factorial design fitted into a randomized complete block design (RCBD) was used with 5 replications. The T. harzianum filtrate significantly increased plant height, number of leaves, and yield. The control showed higher root galling and soil nematode population. Varietal differences showed that F1 Nikita performed significantly better than G. Fuscello. The combination of Trichoderma and F1 Nikita appears effective for managing root-knot nematodes.