Root knot nematodes (Meloidogyne spp.) are among the most dangerous plant pathogens that attacked many hosts from all types of plants. The root-nematode species; M. incognita is the most widespread species all over the world. Copper (Cu) has been used a lot in various control treatments and in different forms as well. In this research, copper nanoparticles (CuNPs) were synthesized using two different methods (chemical and green-biological synthesis). Imaging's of NPs were done using a scanning electron microscope (SEM) to verify the size of the nanoparticles. The morphological images of chemically synthetized NPs (CCuNPs) showed many NPs size with an average of about 126 ɳm. However, the morphological images of CuNPs that prepared using green biosynthesis (GBCuNPs) showed particles with the average of about 85 ɳm. Three concentrations of 100, 150 and 200 ppm of either CCuNPs or GBCuNPs and the chemical nematicide, Nemaprop ® 10G (as a positive control) were tested, in vitro, against 2 nd stage juveniles (J2) of M. incognita. The results of mortality % of J2 exposure to the tested treatments after 24 and 48 hours indicated that the CCuNPs treatments recorded the highest mortality % of J2 after both 24 and 48 hours of exposure followed by that recorded with GBCuNPs treatments, while the lowest mortality % was recorded with Nemaprope ® 10G compared with the check treatment. According to the concentration main effect, the highest reduction percentages were recorded with the 100 and 200 ppm concentrations followed by that recorded with 150 ppm. The interaction between different treatments and its tested concentrations showed significant effective results compared to the check treatment.