The high-resolution infrared spectrum of deuterated fluoroform (DCF3) was studied in the 700 and1200 cm1 regions, with the aim of assigning and analyzing the m4 CF3 asymmetric stretching vibration.The Fermi-type anharmonic coupling between the m4 = 1 and m3 = m6 = 1 rovibrational levels, already men-tioned in an early work of Ruoff et al. [Spectrochimica Acta Part A 31A (1975) 1099–1100], was studiedhere for the first time under high resolution. Assignments in the m3 + m6/m4 band system were confirmedand extended by the identification of the m3 + m6 m6 and m4–m6 bands in the 700 cm1 region, the latterbeing enhanced near the Fermi crossings of the studied levels. Data from both the hot and differencebands were included in the analysis. The close separation of the studied vibrational levels of about14.8 cm1 produces a large variety of resonance crossings which involve levels with Dk ¼ 0; ... ; 6.Besides the Fermi (Dk ¼ 0; Dl ¼ 0) and Coriolis (Dk ¼1; Dl ¼2) resonances, they were accountedfor by inclusion of additional higher-order (Dk ¼2; Dl ¼2 and Dk ¼3; Dl ¼ 0) interaction termsbetween the vibrational states. The least-squares fit of more that 16,000 vibration-rotation transitionsprovides a quantitative reproduction of data in all bands.