The use of reflection high‐energy electron diffraction (RHEED) intensity oscillations to calibrate molecular‐beam epitaxy (MBE) growth rates is an accurate and widely used technique. In order to actually monitor the accumulation of layers during growth, however, the orientation of the substrate must remain fixed. This typically results in much less uniform growth than is obtained with a rotating substrate. As an alternative we have studied near‐threshold photoemission of electrons from a growing surface. Light from an ultraviolet lamp was focused through a sapphire window onto a wafer in a Varian Gen‐II MBE system. A simple biased collector plate monitored the resulting photoemission current. Small oscillations were observed in the collected current after growth of GaAs was initiated. The photoemission oscillations occurred at the same frequency at which RHEED oscillations were subsequently observed. Since no azimuthal orientation is in principle required between the wafer, light source, and collector, with further optimization, this technique may allow for layer accumulation to be monitored during growth on a rotating substrate.