Plasma zinc levels in patients of both sexes suffering from an heterogeneous group of dermopathies were examined and compared with those in patients suffering from psychiatric-neurologic pathologies, in which recent literature has also suggested the role of low zinc levels. The results of the study show a prevalence of effective zinc deficiency in 9.2% of dermatologic patients and 3.9% of neurologic patients, as well as low plasma zinc levels with a different mean, mode and s.d. in comparison to other patients in the control group. These results were statistically significant. The findings are discussed and compared with those reported in the literature.