We present the first detection of the high-resolution ro-vibrational spectrum of the v(3) + v(5) combination band of propyne around 3070 cm(-1). The fully resolved spectrum is recorded for supersonically jet-cooled propyne using continuous wave cavity ring-down spectroscopy (cw-CRDS). The assignments are supported with the help of accurate ab initio vibration-rotation interaction constants (at) and anharmonic frequencies. A detailed analysis of the rotationally cold spectrum is given. (C) 2017 The Authors. Published by Elsevier B.V.