The evaluation of the RigiScan nocturnal recordings of 324 patients, 18 to 72 years old (mean age 49 years), according to guidelines based on normal data, were compared with analysis of these recordings by using the RigiScan Summary Analysis Software Program. This enabled us to provide normal values for this program. We conclude that it should be possible to extend this RigiScan software program in such a way that a probability of normality is given to its user. In patients with corporal veno-occlusive dysfunction a significant lower total event duration was found when compared with the results of patients with normal and abnormal findings.