Tata Institute of Fundamental Research, Howl Bhabha Road, Bombay-400 005 Electron spin-lattice relaxation times (T1e) of toluene and p-xylene anions have been determined by the pulsed saturation recovery technique. Toluene anion exhibits short and nearly temperature independent T1e (1.8��0.4 ��s) in the temperature range studied (188 to 205 K). This is in agreement with the fact that toluene anion has a close lying excited orbital state at about 500 cm-1 and the temperature behaviour follows closely that observed earlier for T1e of benzene anion (orbitally degenerate system) in CW saturation studies. p-Xylene anion exhibits larger T1e's (9.5 ��s at 205 K) and is a linear function of (��/ T) with zero intercept. p-Xylene anion has been estimated to have its first electronic excited state at 1 500 cm-1. It is proposed that Orbach type mechanisms arising from a closely lying excited electronic level are domi��nant for spin-lattice relaxation in toluene anion. In p-xylene anion, however, spin rotation interaction is believed to play the dominant role with Orbach type processes being insignificant since 1 500 cm-1 >> > kT.