An experimental and analytical study was undertaken to determine the effect of saturation upon the gain-bandwidth product of CO 2 regenerative ring laser amplifiers operating below threshold. The analysis considers the effect of the saturable homogeneous medium on the off-resonance as well as the on-resonance gain over a broad range of input powers. Experimental data is in close agreement with theory and indicates that in the region where homogeneous saturation is significant, the amplifier bandwidth varies as the cube root of the ratio of the drive power to the saturation power.