Near infrared (NIR) spectroscopy has been employed for the determination of hydrogen peroxide in antiseptic pharmaceutical preparations where it is found in concentrations of about 3.0% (w/v). Standard solutions containing hydrogen peroxide in the range 0–10% (w/v) were prepared and split into two groups, which were used for partial least squares (PLS1) modelling and for initial evaluation of the model performance. Absorbance spectra, in the wavelength range from 850 to 1800 nm, were obtained using a transflectance probe with optical path of 1.0 mm. The first derivative of the absorption spectra were employed for PLS1 modelling, which requires two factors, resulting in a root mean square error of cross-validation of 0.07% obtained by full cross-validation. The model was evaluated by using prepared and commercial samples of pharmaceuticals containing H2O2 in the range from 1 to 20% resulting in a root mean standard error of prediction of 0.05%.