Hydrogenated amorphous silicon (a-Si:H) films were studied using infrared and Raman spectroscopy. We have experimentally found that ratios of Raman scattering cross-sections for Si–H to Si–Si bonds and for Si–H2 to Si–Si bonds are equal to 0.65 ± 0.07 and 0.25 ± 0.03, respectively. It allows to measure the concentration of hydrogen in a-Si:H films. The developed approach can be applied for in situ control of hydrogen in a-Si:H films and also suitable for thin a-Si:H films on substrates that are opaque in infrared spectral region. Copyright © 2013 John Wiley & Sons, Ltd.