Abstract The rotational dynamics of 2-ethyl naphthalene have been studied from 2°C to 100°C using subpicosecond transient grating optical Kerr effect techniques. After ultrafast librational dynamics have decayed, there remains (⪢3–4 ps) a triple-exponential decay of the orientational anisotropy. The slower two decays exhibit hydrodynamic temperature dependences, corresponding to rotational diffusion. The fastest decay is not hydrodynamic, being temperature independent from 2°C to 40°C. This decay is attributed to the relaxation dynamics of local structures in the liquid.