Conditions for obtaining continuous coatings of copper (thickness range 1.5 to 5μm) on coir fibres have been reported. Activation of the surface of coir fibres was achieved by treating the surface of the fibres with NaOH-HCHO/ammoniacal AgNO3 solution. Copper was deposited on the activated surface of coir fibres from Fehling-formaldehyde solution. The effects of variation in formaldehyde and sodium hydroxide concentrations and pressures inside the coating vessel on deposition rates were determined. The minimum concentrations of NaOH and HCHO required for maintaining a maximum rate of deposition of copper from a solution contaning 10g l−1 copper sulphate were found to be 6.6 g l−1 and 2.5 to 3.5 g l−1, respectively. Optical and scanning electron microscope studies show that relatively more uniform and non-porous copper coatings were obtained when deposition was carried out under reduced pressures. A 5μm thick copper coating on coir fibre prevents the propagation of flame as was shown by flammability tests. Copper coating on coir fibre decreases its electrical resistivity from 2.55×106Ωcm to 4.68×10−3Ωcm with 1.5μm thick coating and 3.76×10−5Ωcm with 5μm thick coating. Reinforcement of polyester with copper-coated coir fibre leads to an increase of about 25% in tensile strength and flexural strength as compared to polyester reinforced with plain coir fibre.