Chitosan is an antimicrobial polysaccharide with potential to control nematodes and elicit plant defense responses. This study aimed to assess the effect of seed treatment with chitosan on the control of Meloidogyne javanica and resistance induction in soybean. In vitro and greenhouse experiments were performed to investigate the effects of chitosan treatments on nematode egg hatching rate, root penetration and reproduction, glyceollin production, and activation of the enzymes guaiacol peroxidase (POX), polyphenol oxidase (PPO), phenylalanine ammonia-lyase (PAL), and catalase (CAT). Chitosan inhibited in vitro egg hatching by up to 99%. Seed treatment reduced M. javanica penetration and development in soybean roots. There was an 81% reduction in nematode reproduction on roots. Seed treatment with chitosan induced the activation of the enzymes POX, PPO, PAL, and CAT as well as phytoalexin biosynthesis. These findings demonstrate that chitosan treatment of soybean seeds is effective in controlling M. javanica and inducing plant resistance.