In this Letter we report on controllable transition of aggregated gamma-Cyclodextrins (gamma-CDs) nanostructures by tuning the concentration of a long chain ionic liquid, 1-dodecyl-3-methyl imidazolium chloride (C(12)mimCl) added to the aqueous solution of gamma-CDs. The gradual increase in concentration of C(12)mimCl first results in the breaking of gamma-CDs aggregates by the formation of inclusion complexes with C(12)mimCl and then self-organizes into a new supramolecular aggregate. This spontaneous transition from one nanostructure to another has been established by spectroscopic and microscopic studies. It is worth to mention that addition of 1-octyl-3-methyl imidazolium chloride (C(8)mimCl) does not lead to any such transition. (C) 2014 Elsevier B.V. All rights reserved.