We investigated the feasibility of a computer-graphics-based method of assessing stereomotion thresholds (Silicon Graphics Stereoview stereoscopic system). Stereomotion thresholds for a rectangle oscillating in depth were determined with the use of a dual randomly interleaved staircase design. In a group of 31 naive observers, the average thresholds of 5.97′ of arc forcrossed stereomotion and 6.00′ of arc foruncrossed stereomotion were comparable to those assessed in earlier work done with optics-based techniques. By assessing the thresholds for a rectangle that was defined either by lateral motion or by changing size, in a group of experienced observers, we were able to show that any potential residual translational motion present in the display would not have influenced the stereomotion thresholds. Our findings suggest that this computer-graphics-based technique may be a reasonable alternative to optics-based methods of assessing stereomotion thresholds.