Atomic hydrogen in silicon‐implanted GaAs samples is studied by photoluminescence. The near‐band‐gap luminescence of GaAs samples subjected to a hydrogen plasma reveals the neutralization effect of the shallow donors. The photoluminescence intensity increases after hydrogen plasma treatment. However, the donor‐related luminescence is drastically reduced, indicating a smaller shallow donor concentration. After a thermal anneal (400 °C, 15 min), the original intensities of donor‐related lines are restored. We confirm the model of an electrically inactive hydrogen‐donor complex and rule out compensating defects created by the plasma treatment.