Temperature dependences are compared for ¹H and ¹³C NMR 1/T ₁ curves relaxation rates in three imidazolium-based ionic liquids (ILs), namely, in [bmim]PF ₆, [bmim]BF ₄, and [emim]CH ₃COO. ¹³C curves show alike behavior for all three ILs and follow a well-known Bloembergen-Pound-Purcell (BPP) equation. On the contrary, an essential part of ¹H curves differ strongly from corresponding ¹³C ones and also have different shapes for different ILs. For the first time, we have detected the specific, two-maximum shape of ¹H relaxation curve for hydrogen atom of C(2)H group of the [emim]CH ₃COO. Assuming that this maximum reflects the correlated rotation of several adjoining ion pairs, we have tried to destroy this rotation by addition of glycerol to the [emim]CH ₃COO. The second, high-temperature maximum has disappeared in the [emim]CH ₃COO–glycerol mixture, and this fact confirms our assumption.