The primary objective of this study is to investigate the influence of different weight percentages of natural fibers on mechanical properties when reinforced with polyurethane foam. This experiment studies were systematically designed and analyzed by response surface methodology (RSM) using Box–Behnken design (BBD) approach. As per the design of experiments, the hybrid polyurethane composites were prepared by using one-shot process. Tensile tests of the hybrid composites were performed over a total of 17 specimens prepared as per ASTM standards. The mathematical models developed to predict the results obtained were in good coherence with the experimental results that are within 95% confidence level for tensile strength. The suggested model’s trustworthiness was evaluated using Analysis of Variance (ANOVA). The optimum weight percentages of groundnut, Roselle, and pineapple leaf fiber are 2, 2, and 5 with 15.7 MPa as tensile strength. © 2019, Springer Nature Singapore Pte Ltd.