The high-resolution infrared spectrum of the nu(3) + nu(8) combination band of propyne (CH3-C CH) is presented for the first time. Continuous-wave cavity ring-down spectroscopy is used to measure this weak infrared band in the 3175 cm(-1) region using a supersonic free jet. The rotational analysis of the experimental spectrum results in accurate spectroscopic parameters for the nu(3) + nu(8) combination vibrational state. Severe perturbations are found for K = 3 and 4 rotational levels that are likely due to near-resonant or non-resonant interactions between the nu(3) + nu(8) and other vibrational states. Moreover three parallel-transition type subbands are observed and their analysis is presented as well. (C) 2014 Elsevier B.V. All rights reserved.