Glasses from the system BaO-SrO-ZnO-SiO2 with different Ba/Sr ratios were characterized regarding crystallization behavior as well as the thermal expansion of almost fully crystallized glasses. Depending on the SrO concentration, different crystalline phases precipitate from the glasses. Those with low SrO concentrations precipitate crystals with the structure of low-temperature BaZn2Si2O7 as one of the major phases. Higher SrO concentrations cause the formation of Ba1-xSrx Zn2Si2O7 solid solutions with the structure of high-temperature BaZn2Si2O7. Both, the low-as well as the high-temperature phase exhibit very different thermal expansion behaviors ranging from a very high coefficient of thermal expansion in the case of the low-temperature phase to a very low coefficient of thermal expansion in the case of the high-temperature phase. The glass-ceramics with the highest and that with the lowest coefficient of thermal expansion measured between 100 degrees C and 800 degrees C show a difference of 7.9 x 10(-6) K-1, which is caused solely by a substitution of BaO with SrO. In contrast, the maximum variation in the thermal expansion of the glasses was only 1.5 x 10(-6) K-1. The microstructure of sintered and afterward crystallized glass powders was analyzed via scanning electron microscopy and showed crack-free samples with low porosity.