The evolution of sandwich structures based on biodegradable and recyclable materials has created an interest in the study of their static and dynamic characteristics. In this work, experimental and numerical investigations are carried out on the vibration characteristics of a sandwich beam made using polypropylene honeycomb as the core and a woven jute/epoxy laminated composite as the face sheet. The numerical investigation is performed using the commercial finite-element analysis software Ansys. The validation of the finite-element model is done by comparing the natural frequencies evaluated numerically with the natural frequencies obtained experimentally. Also, an optimisation study on the modal characteristics of the sandwich beam is carried out based on the Taguchi L9 array by considering various parameters - namely, core thickness, fibre orientation and the number of natural fabric layers. From the optimisation study, it is found that the best dynamic characteristics are obtained from the specimen with the following optimum parameters: core thickness of 10mm or smaller, number of layers between two and three and fibre angle orientation of around 20°. © 2020 ICE Publishing. All rights reserved.