Experiments were conducted to investigate the effect of Arthrobotrys oligospora against Meloidogyne incognita infecting tomato plants. Effect of A. oligospora on capture of M. incognita juveniles and the trapping rate in–vitro were calculated. Different density of A. oligospora i.e.1, 3 and 5% of soil weight used to evaluate its effect on nematodes and plant growth parameters of tomato plants under green-house conditions. Data showed that the A. oligospora formed adhesive, three-dimensional networks and the trapping organs have the ability to trap the second stage juveniles of M. Incognita. In-vitro test was carried out by exposing the nematode juveniles to A. oligospora culture at 24, 48 and 72 hours. The trapping rate of juveniles by the trapping organs increased by increasing the exposure time at (72 hours). Results of in-vitro test showed significant reduction in nematode criteria comparing to the untreated control. Tomato growth parameters were also significantly enhanced.Thus; the present study showed the possibility of using A. oligospora as a bio-control agent to root-knot nematode, M. incognita.