Chemical shift tensors (CST) for the protonated aromatic carbons in polystyrene are presented. Experimental difficulties preclude the direct measurement of these tensors. The values reported are obtained from quantum chemical calculations on 2-phenyl propane using the 6-31G basis set, after testing other basis sets against similar compounds for which the chemical shift anisotropies are known. Corrections for narrowing of the chemical shift anisotropy due to the molecular motions at finite temperatures are also reported.