Column‐IV (Si, Ge, and Sn) and column‐VI (S, Se, and Te) impurities are used to dope high‐purity layers of vapor epitaxial GaAs. Resistivity and Hall data on a large number of samples show that the common donors in GaAs (assumed to be column‐IV impurities on gallium sites and column‐VI impurities on arsenic sites) are compensated by acceptor centers which are donor impurity‐vacancy complexes. These acceptor complexes are tentatively identified as column‐IV impurities on gallium sites associated with single gallium vacancies and column‐VI impurities on arsenic sites associated with single arsenic vacancies.