The ³⁵Cl NQR Zeeman effect in a single crystal of perchloropentafulvalene has been studied for the four lines v₁ = 37245.5, v₂ = 37080.0, v₃ = 36095.0 and v_{4 =} 36019.1 kHz at 291.5 K by a pulsed FT NQR system. The asymmetry parameters of v_1, v_2, v₃ and v₄ are 0.10, 0.11, 0.15 and 0.17, respectively. The twist angle between the two five-membered rings is estimated to be 40°, obtained from the directions of the principal X axes for v₃ and v₄. The results of this work are compared with those of an X-ray three-dimensional analysis.