UV (240-370 nm) and IR (3200-1500 cm(-1)) absorption cross-sections of HCHO, HCDO, and DCDO in a bath gas of N-2 at atmospheric pressure and 296 K are reported from simultaneous measurements in the two spectral regions. Cross-sections were placed on an absolute scale through quantitative conversion of formaldehyde to CO and HCOOH by titration with Br atoms, also monitored by FTIR. The integrated UV absorption cross-sections of HCHO, HCDO, and DCDO are equal to within the experimental uncertainty.