Root-knot nematode (Meloidogyne incognita) is one of the most damaging species of plant nematodes to vegetable crops. The efficacy of ethanolic, methanolic and aqueous extracts of garlic for suppression of M. incognita infecting tomato (Solanum lycopersicum L.) plants were evaluated under greenhouse conditions. Results showed that all tested extracts caused significant reductions (P≤0.05) in the nematode criteria, final population, rate of reproduction and percentages of nematode reduction compared to nematicide and non-treated plants. The methanolic extract at 6 ml/plant caused the best effect on the previous criteria (5536, 1.85 and 92.43%) respectively, compared with the non-treated control. On the other hand, all tested extracts decreased the negative effects of root-knot nematode and an enhancement in the growth parameters of tomato plants. Where the methanolic extract achieved the best results at the highest concentration in both measures of vegetative growth and the chemical content of defensive compounds for plants.