Hydroxyapatite (HAP), a well known biontaterial, was synthesized by a novel technique using agarose gel in a high alkaline medium at a relatively low temperature 85 degreesC. The XRD analysis of the as-synthesized material revealed the absence of either brushite or alpha or beta tricalcium phosphate phases. Sintering studies at 750 and 1200 degreesC revealed the conversion of HAP into pyrophosphate without leaving any additional phases. A considerable decrease in the transformation temperature of HAP phase to that of alpha-calcium pyrophosphate (alpha-CPP) phase was found compared to the reported values. (C) 2003 Elsevier Science B.V. All rights reserved.