The C-13 chemical shifts of isolated polyacetylene chains bearing a singly or doubly charged defect have been studied using the GIAO approach through the B3LYP exchange-correlation functional with the pcS-2 basis set. Our results show that the distributions of chemical shift reflect the detailed structural distortions caused by the charged defects on the backbones of the polyenic chains. The results also show large variations of chemical shift between the corresponding charged chains with different charge states, which could be detected in nuclear magnetic resonance experiments. (C) 2011 Elsevier B.V. All rights reserved.