ThickSi0.9Ge0.1relaxed layers grown by chemical vapor deposition on Si(100) oriented substrates are investigated by photoluminescence (PL) spectroscopy. Resolved excitonic near-band-gap luminescence is observed in as-grown and hydrogen treated samples. Phonon assisted transitions are also well identified. The effect of hydrogenation is to enhance the luminescence related to the near-band gap. This enhancement is correlated with a quenching in the dislocation related PL especially for the D3–D4 bands and the T band. This indicates that hydrogenation passivates radiative centers inside dislocation cores which are responsible, beside nonradiative channels, for the quenching of SiGe band-gap edge luminescence.