The (1, 0) band of the A(2)II-X(2)Sigma(+) transition of the CS+ cation has been measured in absorption at Doppler-limited resolution, between 12 400 and 13 000 cm(-1). The spectrum was recorded using differential velocity modulation detection and a Ti: sapphire laser as the near-infrared light source. The upsilon = 1 A(2)II upper state of the band is perturbed by the upsilon = 10 level of the ground state. A deperturbation analysis using > 300 rotational lines was carried out to derive accurate ground-and upper-state parameters, The ground-state rotational and fine-structure constants are in very good agreement with those from a Fourier transform emission study in which the ground-state constants were derived from combination differences.