We present results obtained when a TEA‐CO2laser pulse is radially incident on a dense hydrogenZ‐pinch plasma. Perturbations of the plasma column are visible on high‐speed streak photographs. Spectral measurements indicate that stimulated Brillouin scattering in the underdense plasma regions is the dominant mechanism for the observed backscattering of laser radiation by the plasma column. The time behavior of the backscattered signal can be very complex, both prompt and delayed backscatter having been observed under ostensibly identical experimental conditions. The backscattered power is typically 1–2% of the incident laser power.