The incorporation of hydrogen in ZnSe:N and ZnSe:Cl films grown by gas source molecular beam epitaxy (GSMBE) using elemental Zn and H2Se as source material has been investigated. The hydrogenation behavior was found to be significantly enhanced when nitrogen was used as a dopant, and typically resulted in highly resistive films. On the other hand, Cl‐doped ZnSe films showed a hydrogen concentration at or near the background levels independent of the Cl concentration. ZnSe was also grown by conventional molecular beam epitaxy with intentionally introduced H2in order to clarify the source of the hydrogen. Significant hydrogen incorporation was observed in the MBE‐grown ZnSe:N layers only when hydrogen gas was introduced. Injection of hydrogen in excess of the amount generated during typical GSMBE experiments was found to give rise to an unambiguous increase in the hydrogen concentration, but with a hydrogen:nitrogen ratio less than that measured in GSMBE films. ©1995 American Institute of Physics.