The Q branch in the Raman spectrum of compressed HD has been observed at room temperature and at 85 K. At low densities, collision broadening has been observed and the results analyzed using the theory of Gray and Van Kranendonk. Semiquantitative agreement is found between the observed and calculated broadening coefficients. At medium and high densities, motional narrowing of the Q branch occurs. Although qualitative agreement is found between the results and the theory of Alekseev and Sobel'man, a detailed comparison of the theoretical and observed profile shows that both frequency and intensity perturbations due to collisions have been omitted from the theory. Finally, a number of inconsistencies between the frequency perturbation observed by May et al. for H2 and the present observations are noted. These are not understood.