ABSTRACT Designing a scaffold with appropriate level of porosity, mechanical strength and bioactivity is essential for bone tissue engineering. In this study, a hydroxyapatite (HAp)/diopside nanocomposite scaffold was fabricated through foam replication method. The optimal sample was specified using central composition design (CCD) statistical method regarding HAp to diopside weight ratio, sintering temperature and lubricant content. A HAp/20 wt.% diopside sample containing 0.64% of lubricant sintered at 1200°C was chosen as the optimal sample and compared to a pure HAp sample. A porosity percentage of 84.48% and a compressive strength of 0.63 MPa was recorded for the optimal sample. The bioactivity evaluation in simulated body fluid (SBF) indicated that the HAp/20 wt.% diopside scaffold presented more formation of Si-OH layer and apatite nucleating site in comparison with the pure HAp scaffold. Based on the results, the HAp/20 wt.% diopside nanocomposite scaffold can be an appropriate candidate for bone tissue engineering applications.