Ab initio complete active-space self-consistent field (CASSCF) and second-order Multireference Moller-Plesset perturbation (MRMP2) calculations were performed to examine the S-1-S-0 internal conversion of 6-cyanoazulene (6CNAZ). The azulene skeletons of 6CNAZ in S-0 and S-1 have features that resemble those of azulene. The stable geometry in S-0 is characterized by (i) a C-2v structure, (ii) an aromatic bond-equalized structure in which all the peripheral skeletal bond distances resemble an aromatic CC bond distance, and (iii) a single bond character of the transannular bond. The stable geometry in S-1 is characterized by a nonaromatic C-2v structure. Contrary to similarities of the stable geometries in S-0 and S-1 between 6CNAZ and azulene, the conical intersection (S-1/S-0-CIX) of 6CNAZ is different from that of azulene. The S-1/S-0-CIX of 6CNAZ takes a planar structure, whereas that of azulene takes a nonplanar structure in the seven-membered ring (Amatatsu, Y.; Komura, K. J. Chem. Phys. 2006, 125, 174311/1-8). On the basis of those computational findings, we predict the photochemical behavior of 6CNAZ in the S-1-S-0 internal conversion.