The present article details the formation of lanthanum-modified apatites and the binding process of tartrate ions with these obtained apatites. Chemical analyses, FT-IR and P-31 NMR spectroscopies XRD, powder, TGA, and TEM analyses were employed for studying the reaction between Ca-10(PO4)(6)(OH)(2)(HAp) or Ca-10(PO4)(6)(F)(2) (FAp) and LaCl3. The reaction was found to take place mainly through partial dissolution of the apatite followed by precipitation of a new phase containing lanthanum phosphate. When La3+ was introduced in the presence of L(+)-tartaric acid (TAH(2)), no fundamental changes were observed in the HAp or FAp structures. However, there did occur a formation of a new phase of Ca or/and La tartrate salt. (C) 2008 Elsevier Inc. All rights reserved.