In this research work, the effect of parameters such as orientation, length, and shape of fibers were investigated. Flat and waved carbon steel fibers with 15 mm length were used with different orientations. The effect of orientation and shape of fibers on composite modulus was investigated. Fiber-reinforced epoxy resin with 30 mm waved and endhooked fibers were also investigated. The theoretical results obtained using Halpin-Tsai model are in good agreement with the experimental results for all the shapes and orientations. Because of the mechanical interlock, the shaped fibers can bridge matrix cracks effectively and improve composite's modulus. Improvement of modulus using shaped fibers for certain orientations has been achieved. The results obtained are useful in the application of texturising on the synthetic fibers in polymeric materials and provide flexibility in design of any demanded shape through improving modulus at different angles. (c) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 469-474, 2011