The Fourier transform spectrum of the vibration-rotational bands (v_{2}) and (v_{5}) of gaseous fluoromethane ({ }^{13} \mathrm{CH}{3} \mathrm{~F}) was measured at an unapodized resolution (0.0041 \mathrm{~cm}^{-1}). Among the assigned lines, 102 belonged to the (\Delta k= \pm 2) perturbation-allowed transitions to the doubly degenerate vibrational state (v{5}=1). Combination differences were generated for the ground state of ({ }^{13} \mathrm{CH}{3} \mathbf{F}) from the wavenumbers of the allowed and forbidden vibration-rotational transitions to (v{\mathrm{s}}), (=) 1 level. They were used in a simultaneous least squares fit with the previously measured microwave, submillimeterwave. and far infrared transition frequencies of the pure rotational transitions in the ground state and with the combination differences generated from the allowed transitions to the (v_{3}=1) state of ({ }^{13} \mathrm{CH}{3} \mathrm{~F}) (Pracna. Klee, Winnewisser. Papoušek, Yen-Chu Hsu. and Hann-Sen Chen. J. Mol. Spectrosc: 156, 217-226 (1992). This made it possible to determine precisely for the first time (A{0}) and (D_{\kappa}^{0}) for ({ }^{13} \mathrm{CH}{3} \mathrm{~F}: A{0}=(5.1824246 \pm 0.0000015) \mathrm{cm}^{1}, D_{\kappa}^{0}=(70.912 \pm) (0.033) \times 10^{-6} \mathrm{~cm}^{-1}). «c: 1993 Academic Press. Inc.