The present study was aimed at designing a novel bimodal fiber diameter distributed electrospun hydroxyapatite/nylon-6 (HAp/N6) biocomposite nanofiber mat for bone tissue engineering. The manufacturing of pure N6 fibers and biocomposite fibers was explored by an electrospinning process. The synthesized HAp/N6 composite mats were characterized by XRD, TGA, FE-SEM, EDS, and TEM analyses and water contact angle measurements. The results revealed that fibers of distinct sizes (nano and true-nano scale) were obtained with the addition of a wide range (1-10 wt.%) of HAp. Conversion of pristine hydrophobic N6 fibers (130.3 degrees) to super-hydrophilic (0 degrees) composite fibers by simple blending of different amounts of HAp with N6 solution prior to electrospinning could make N6 more bio-compatible for hard tissue engineering. Biomineralization was carried out by immersing the composite into simulated body fluid for different lengths of time. Results showed that the nanocomposite had a better ability to form apatite layers on the surface of the fibers compared to the pristine fibers. Therefore, our results suggest that this newly developed HAp/N6 hybrid scaffold may have potential for bone tissue engineering. (C) 2013 Elsevier Ltd. All rights reserved.