Barium titanate added MgO–Al2O3–SiO2–TiO2 (MAST) glass ceramic was prepared to obtain a range of dielectric constant 6–8 for microwave application using naturally occurring materials, e.g. talc, alumina and china clay. Firstly, the MAST glass was prepared by the conventional melt quench process. Barium titanate (BaTiO3) powder (5–30 wt%) was added to the obtained MAST glass frit. Ceramic pellets were prepared from homogeneously ground and mixed powders by uniaxial pressing. X-ray diffraction patterns of the sintered pellets (at 1200 °C) show well-defined peaks of cordierite, BaTi5O11 and Ba2Ti9O20, and some anorthite and magnesium titanium oxide phases. The evolution of BaTi5O11 and Ba2Ti9O20 compounds is very much desirable since they possess excellent microwave dielectric properties. Their high dielectric constant and high quality factor would increase the dielectric constant of the compositions without degrading the loss tangent value. The microstructure shows the crystalline and amorphous (glass) phases. The dielectric constant of the prepared glass ceramic samples varies in the range 6.0–8.0 with the tan delta of 10−2 in the X-band, depending on the composition, phase and microstructure of the specimens. The tailored dielectric constant glass ceramic will be useful for microwave device applications.