In this paper we show that nanocrystalline aluminium can be electrodeposited from the ionic liquid 1-butyl-1-methylpyrrolidinium chloride ([Py-1,Py-4]Cl/AlCl3) (40/60 mol%). The study comprises electrochemical experiments such as cyclic voltammetry, constant potential electrolysis, SEM and XRD measurements. Thick and uniform layers of aluminium are obtained from [Py-1,Py-4]Cl/AlCl3 with an average crystal size of 20 nm at 100 degrees C. Aluminium deposits obtained from 90:10 vol% and 80:20 vol% of [PY1,4]Cl/AlCl3 and [EMIm]Cl/AlCl3 are nanocrystalline at 100 degrees C. The presence of imidazolium cations seems to alter the electrode/electrolyte interface to some extent as nanocrystalline and microcrystalline aluminium deposits are obtained from the ionic liquid mixtures at compositions of 70:30 vol% of [Py-1,Py-4]Cl/AlCl3 and [EMIm]Cl/AlCl3 and below. (C) 2012 Elsevier Ltd. All rights reserved.