Corneal endothelial permeability and aqueous humor dynamics were studied in 17 non-treated normal pressure glaucoma patients in order to analyse the relevance of these parameters in the pathophysiology of this disease. Corneal endothelial permeability and aqueous humor flow were measured by fluorophotometry and aqueous outflow facility was determined by tonography. The results were compared with those of 17 healthy controls of similar age. The mean corneal endothelial permeability values and the aqueous flow and outflow facility values of the patients did not differ significantly from those of the healthy controls (P = 0.8, P = 0.2 and P = 0.5, respectively). Normal pressure glaucoma does not affect the corneal endothelial permeability. The aqueous humor dynamics are not primarily involved in the pathophysiology of normal pressure glaucoma.