Hydroxyapatite (HAp) nanospheres were synthesized in large scale using high gravity method. The effects of flow rates (300, 500 and 700 mL/min) and rotating speeds (1000, 2000 and 3000 rpm) on the size, distribution and morphology of nanoparticles were studied. The liquid flow rate and rotation speed was found to have a great influence on the formation of nanoparticles and uniform size distribution. The particle size decreased with an increase in the rotation speed of the RPB. The particle size was observed to be smaller at a lower liquid flow rate compared to that of the high liquid flow rate. TEM images of the granular HAp nanoparticles clearly displayed the spherical shape of nanoparticles. Densely assembled arranged nanospheres with diameters of 20-40 nm were observed at various rpm values. The obtained nanospheres appeared to be single crystalline from the image and SAED pattern analyses. In vitro cellular analysis showed very good improvement in the cell adhesion. For mechanical analysis, HAp/HMWPE composite was fabricated. The smaller size of HAp particles provided a relatively homogenous mixture of HAp and HMWPE which ensured the good mechanical strength. © 2011 Elsevier B.V.