Chitosan (poly-N-acetylglucosamine) is a natural and biodegradable biopolymer. Chitosan and its derivatives can be variously used as a permeability control agent and an antimicrobial compound. So, addition of three molecular weights of fungal chitosan (1.9x105; 1.4x105 and 2.1x104 Da) at soil as well as castor oil and Nemacur 10% G (chemical control) significantly reduced (p≤0.05) root-knot nematode infection caused by Meloidogyne incognita and improved growth of banana plants cv. Williams as compared with the control. Fungal chitosan type at Mw (2.1x104 Da) gave the most effective results in reducing the number of galls and the final population of nematode. On the other hand, fungal chitosan type at Mw (1.9x105 Da) surpassed the other tested materials and showed relatively maximum growth parameters as compared with the other treatments and the check.