Bioactive ceramics based on CaMg(SiO3)2 are proposed for osteogenic differentiation of human adipose stem cells. Specimens of nominal compositions x Ca3(PO4)2 - (1-x) CaMg(SiO3)2 x = 100, 40 and 20 wt.%), were obtained by solid state sintering of mixtures of a fine synthetic precursor of Ca3(PO4)2 and synthetic CaMg(SiO3)2 powders. Complete microstructural analysis of the sintered materials, including X-ray diffraction and field emission scanning electron microscopy with microanalysis (FE-SEM-EDS), is presented. The single phase material (TCP) was beta-Ca3(PO4)2 and the composites (60D-40TCP and 80D-20TCP) were mainly constituted of CaMg(SiO3)2 and beta-Ca3(PO4)2; a small amount of CaSiO3 (about 3 wt.%) was also homogeneously distributed in the microstructure. Mechanical characterisation in terms of the Weibull distribution of tensile strength determined by the Diametrical Compression of Discs Test (DCDT) is discussed. Alkaline phosphatase activity (ALP) assay of human adipose mesenchymal stem cells (hASCs ) was performed in order to evaluate bioactivity and osteogenic potential of studied materials. Composition and temperature determine phase development in the materials, in agreement of the equilibrium relationships. Strength values of the composite materials are significantly higher than those of TCP. hASCs are viable in all materials and proliferation is increased in osteogenic culture conditions. All materials support early osteogenesis of hASCs which apparently is dependent of the donor. Material with 80wt.% diopside combines the best mechanical and bioactive behaviors. Acknowledgements Work performed in the frame of Cost action MP1301, NEWGEN and projects MAT2013-48426-C2-1-R and PIE 20160E097 (Spain) and Jane and Aatos Erkko foundation (Finland)