Using coupled-cluster with single and double substitutions (CCSD) and based on the density functional theory (DFT), geometry optimization calculations have been performed for the ground state of InCl, and the spectroscopic constants are obtained. The potential energy curve, the spectroscopic constants and the radiative lifetimes for the vibrational levels of the C(1)Pi state are also computed by the use of CCSD, the results being in accordance with the experimental values, and showing that the C(1)Pi system is a quasi-bound state with a shallow well. Considering the effects of avoided crossing and barrier penetration, the maximal vibrational quantum number of the C(1)Pi state should not be more than 4. (C) 2002 Published by Elsevier Science B.V.