The rotational dynamics of 1-alkyl-3-methylimidazolium-based ionic liquids has been investigated by monitoring their inherent fluorescence with the intent to unravel the characteristics of the emitting species. For this purpose, temperature-dependent fluorescence anisotropies of 1-alkyl-3-methylimidazolium (alkyl = ethyl and hexyl) ionic liquids with anions such as tris(pentafluoroethyl)trifluorophosphate ([FAP]), bis(trifluoromethylsulfonyl)imide ([Tf2N]), tetrafluoroborate ([BF4]), and hexafluorophosphate ([PF6]) have been measured. It has been observed that the reorientation times (tau(r)) of the ionic liquids with an ethyl chain scale linearly with viscosity and were found to be independent of the nature of the anion. The experimentally measured ?r values are a factor of 3 longer than the ones calculated for 1-ethyl-3-methylimidazolium cation using the StokesEinsteinDebye (SED) hydrodynamic theory with stick boundary condition, which suggests that the emitting species is not the imidazolium moiety but some kind of associated species. The reorientation times of ionic liquids with a hexyl chain, in contrast, follow the trend tau([FAP])(r) > tau([Tf2N])(r) = tau([BF4])(r) > tau([PF6])(r) at a given viscosity (eta) and temperature (T). The ability of the ionic liquids with longer alkyl chains to form the organized structure appears to be responsible for the observed behavior considering the fact that significant deviations from linearity have been noticed in the tau(r) versus eta/T plots for strongly associating anions [BF4] and [PF6], especially at ambient temperatures.