One hundred Quinqueloculina impressa individuals were buried under 4 cm of sand in each of four cores. After 3.5 days the cores were sectioned to determine the vertical movement of individuals. Individuals moved farther upward than downward in all cores: 95% of the individuals were found between the 2.0 and 5.5 cm depths, as predicted by a model based on effective sediment overburden pressure controlling foraminiferal velocity. The distribution of individuals in the cores could not be produced by a one-dimensional random walk: Upward moving individuals tended to move a greater distance than expected while downward moving individuals moved less far. While rates of subsurface motion are controlled by effective sediment overburden pressure, the direction of motion, and thus the ultimate subsurface distribution, may be more affected by such things as chemical gradients or bioturbation. These factors were not duplicated in this laboratory experiment.