Correlations between the surface chemistry of etched, (100) orientedn‐GaAs electrodes and their subsequent photoelectrochemical behavior have been probed by high‐resolution x‐ray photoelectron spectroscopy. GaAs photoanodes were chemically treated to prepare either an oxide‐free near stoichiometric surface, a surface enriched in zero‐valent arsenic (As0), or a substrate‐oxide terminated surface. The current‐voltage (I‐V) behavior of each surface type was subsequently monitored in contact with several electrolytes.