The present study investigates the hydration of calcium sulfoaluminate (CSA) cement blended with blastfurnace slag (BFS). BFS was added at dosages of 0, 30, 50 and 70% of the binder mass. The samples were cured for up to 360 days and characterized using various analytical techniques. The obtained results indicate that BFS-blended CSA cement incorporating 30% BFS exhibits compressive strength comparable to that of the sample solely consisting of CSA cement. BFS incorporation in CSA cement leads to the formation of more stratlingite, possibly preventing the development of porosity due to the destabilization of CAH(10). The main hydration products of CSA cement blended with BFS are identified as ettringite, monosulfate, Al(OH)(3) and stratlingite, similar to those forming during the hydration of CSA cement, though stratlingite increasingly forms at higher BFS contents.