Impact touhgness of coir fiber-reinforced epoxy composites have been investigated. Coir fibers being obtained from local sources were underwent alkaline treatment by soaking them in a solution containing 10 wt% of NaOH prior to being embedded into epoxy. Five different theoretical fiber volume fractions,Vf = 0%, 10%, 20%, 30% and 40%, were considered. Specimens were cut from composite plate panels produced using press-mould technique. Impact test was carried out in accordance with the ASTM D5941 standard for Izod impact. Photo macrographs of representative fractured specimens were closely observed and analyzed to determine their failure mechanism. It was found that the highest impact toughness of 0.075 J/mm2 was obtained at Vf30%. Whilst debonding followed by fiber pull-out dominated the failure mode at higher Vf, multiple fracture and broken into pieces were observed for pure epoxy and 10% Vf specimens.