Updated project metadata. Human primary granulosa cells (GCs) derived from women, undergoing oocyte retrieval, can be cultured and are a cellular model for the study of human ovarian functions. In vitro they change rapidly, resembling initially cells of the preovulatory follicle and then cells of the corpus luteum. They are derived from individual patients and their different medical history, lifestyle and age lead to heterogeneity. Thus, cells can rarely be ideally matched for cellular experiments or, if available, only in small quantities. We reasoned that cryopreservation of human GCs may be helpful. Previous studies indicated feasibility of such an approach, but low survival of GCs was reported and consequences on GC functionality were only partially evaluated. We tested a slow freezing protocol (employing FCS and DMSO) of GCs upon isolation from follicular fluid. We compared cryopreserved and subsequently thawed cells with fresh, not cryopreserved ones, from the same patients. About 80 % of human GCs survived freezing/thawing. Neither morphology, nor levels of cell-cell contact, mitochondrial and steroidogenic genes were different between the two groups in cells cultured for 1-5 days. A proteomic analysis revealed no statistical significance in the abundance of a total of 5962 proteins. Both groups produced comparable basal levels of progesterone and responded similarly to hCG with elevation of progesterone. Taken together, we describe a rapid and readily available method for the cryopreservation of human GCs. We anticipate that it will allow future large-scale experiments and may thereby improve cellular studies with human ovarian cells.