This paper presents an experimental investigation on modal analysis for natural fibre composite beams. The composite beams were developed using natural fibres such as sisal, banana, and bamboo fibres mixed with epoxy resin as a matrix material. Natural fibres are biodegradable and have low cost and are eco-friendly. The composite beams were developed using a hand-lay-up method for various angles such as 0°-90° and 45°-45°. Chemical treatments were used for improving interfacial shear strength between fibres and matrices. Impact testing and modal analysis were conducted on natural fibre composite beams. The natural fibre composite beams were found to have good properties for vibrations. The results indicated that natural fibre composite beams have good properties for mechanical strength and damping properties. The natural fibre composite beams can be used for applications where there is a need for light weight and high sensitivity for vibrations.