A modified mixed oxide synthetic route has been developed for the synthesis of the columbite-like phase of magnesium niobate, MgNb 2O 6 (MN). Magnesium carbonate hydroxide pentahydrate was employed as a source of magnesium, with the formation of columbite phase investigated as a function of calcination temperature and dwell time by XRD and DTA. The particle size distribution of the calcined powder was determined by laser diffraction, with the morphology, phase composition and crystal structure determined via SEM, TEM and EDX techniques. It has been found that the Mg 4Nb 2O 9 phase tends to form together with the columbite-type phase MgNb 2O 6, although a single columbite-like phase of MgNb 2O 6 was obtained for a calcination temperature of 1150°C with a dwell-time of 4 h. ©