Matrix isolation infrared spectroscopy has been combined with MP2/6-31+G(d,p) calculations to characterize the 1:1 hydrogen-bonded complexes between H2O2 and the bases NH3 and N(CH3)(3). Most obvious from the spectra of these complexes and their deuterated analogues is the shift to lower frequency of the hydrogen-bonded O-H or O-D stretching bands relative to the isolated monomers. The experimental shifts are in good agreement with the computed shifts. Perturbation of the O-O-H bending mode was also observed, along with shifts of certain vibrational modes of the base subunits in the complexes. Surprisingly, the experimental intensities of the product bands are low when compared to other hydrogen-bonded systems and to the computed intensities.