In this paper we report on the synthesis of aluminium oxide nanoparticles in two different air and water stable ionic liquids namely, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) amide [BMP]TFSA and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) amide [EMIm]TFSA. The ionic liquids [BMP]TFSA and [EMIm]TFSA exhibit biphasic behaviour beginning with an AlCl₃ concentration of 1.6 mol L^–1 and 2.5 mol L^–1, respectively. Different aluminium oxides were prepared by the hydrolysis of AlCl₃ dissolved in the employed ionic liquids, followed by calcinations. AlCl₃·6H₂O was found to be the main hydrolysis product of the AlCl₃ containing ionic liquids. The as-prepared AlCl₃·6H₂O is subject to thermal decomposition producing different forms of transition oxides, depending on the original liquid composition. Alumina was also obtained by hydrolysis of as-prepared AlCl₃·6H₂O by NH₄OH solution. Hydrolysis of the upper phase of the biphasic mixture of 3 M AlCl₃–[EMIm]TFSA with NH₄OH produces transparent alumina which is converted into α-Al₂O₃ with a low amount of δ-Al₂O₃ after calcinations at 1000 °C. The formation of pseudoboehmite and γ-Al₂O₃ as intermediates are observed at 200 °C and 550 °C, respectively. The obtained pseudoboehmite is mesoporous with an average pore diameter of 3.8 nm and a high surface area of 226 m² g^–1. The chloroaluminite obtained by hydrolysis of the homogenous mixture of 1 M AlCl₃–[BMP]TFSA undergoes thermal decomposition yielding amorphous alumina at 200 °C, which transforms completely to well crystallized α-Al₂O₃ at 1000 °C. The obtained α-alumina is porous with an average pore size of about 10 nm. This suggests that the ionic liquid [BMP]TFSA acts as a template and that it decomposes thermally at elevated temperature producing pores.