Cashew nut oil-based benzoxazine monomer has been synthesized applying solvent-less method through the Mannich reaction of cashew nut shell oil as phenol, amine, and formaldehyde. A difunctional 1,3-benzoxazine is synthesized using diaminodiphenyl methane as the amine component. H-1 and C-13-nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy are used to characterize the structure of the monomers. Wood flour is used to prepare composites, making both reinforcement and matrix resin the materials derived from renewable resources. Observation of catalytic effects on DSC exothermic temperature and crosslink density by the added wood flour is discussed. (C) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 127: 2710-2714, 2013