Theoretical expressions for the collision-induced absorption spectra of a dipolar and a homonuclear diatomic pair are presented. For the dipolar species, the line strengths and transition frequencies are taken from the HITRAN database, whereas for the homonuclear molecule, the polarizability matrix elements and spectroscopic parameters are obtained from the literature. As specific examples, we consider the double fundamental vibrational transition in CO2−N2, and the H2O−N2 transition in the region of the nitrogen fundamental. For the former pair, the theoretical results are in good agreement with experimental data. For the latter pair, we show that the collision-induced absorption for high humidity conditions is larger than that of N2−N2 pairs above 2500 cm−11, but for lower wavenumbers, it is much weaker than the measured foreign continuum resulting from the far wings of allowed transitions.