Human granulosa cells (GCs), obtained during medical reproductive procedures can be cultured and are a cellular model for the human ovary. Oxygen concentrations are regarded as important regulators of GCs. We examined consequences of low (1%) O2 versus standard atmospheric conditions in cultured human GCs for four days. A proteomic analysis of three pools of human GCs was performed. While differences between the pools of GCs were noted, the abundance of 133 proteins was significantly increased in hypoxia in all samples, whereas the abundance of 391 proteins was decreased.