A theoretical study of spin-rovibronic levels arising from Renner-Teller and spin-orbit couplings in the ground X(2)Pi state of BrCN+ is reported. Vibronic energy levels of Sigma, Pi, Delta, Phi symmetry, up to approximate to 9000 cm(-1) have been calculated variationally, using highly accurate ab initio full-dimensional potential energy surfaces and taking explicitly into account the geometry dependence of the spin-orbit coupling. Results are compared to available experimental data. (c) 2005 Elsevier B.V. All rights reserved.