High-resolution absorption spectra of gas-phase monomethylamine (MMA, {\text{CH}}_{\text{3}}{\text{NH}}_{\text{2}} ) and dimethylamine [DMA, {\left({\text{CH}}_{\text{3}}\right)}_2 NH] in the region of the first overtone of the NH stretch vibration are reported. Measurements were performed with a near-infrared laser spectrometer based on the cavity-ringdown (CRD) detection technique. The minimum detectable absorption coefficient for the CRD detection setup is {\alpha }_{\text{min}}=1.55\times {10}^{-8}{\text{cm}}^{-\text{1}} (for SNR = 1). This corresponds to detection limits of 350 parts in {10}^9 (ppb) for MMA and 1.6 parts in {10}^6 (ppm) for DMA in synthetic gas mixtures under interference-free conditions, or 10 ppm and 60 ppm for MMA and DMA, respectively, in the case of gas mixtures such as exhaled human breath containing {\text{H 2}}_{}\text{O} , {\text{CO}}_{\text{2}} , and other absorbing gases in this range.