This preliminary study focuses on the effect of adding SrO to a Ti-containing quaternary phosphate glass system denoted by P2O5–Na2O–CaO–TiO2. The following four different glass compositions were manufactured: 0.5P2O5–0.17Na2O–0.03TiO2–(0.3−x)CaO–xSrO where x = 0, 0.01, 0.03 and 0.05. Structural characterisation revealed glass transition temperatures in the range 427–437°C and the presence of sodium calcium phosphate as the dominant phase in all the glasses. Degradation and ion release studies conducted over a 15-day period revealed that the Sr-containing glasses showed significantly higher degradation and ion release rates than the Sr-free glass. Cytocompatibility studies performed over a 7-day period using MG63 cells showed that the addition of 5 mol% SrO yielded glasses with cell viability nearly equivalent to that observed for quaternary TiO2 glasses.