Rubella antibody titers were measured in psoriatic patients using the HAH test. Some patients received immuno-suppressive therapy while others did not. The difference between antibody titers in both groups was not significant. Antibody titers in patients with verified rubella did not change after a booster vaccination. These results are discussed in view of Epstein’s assumption of an immunologic block in psoriatic patients. At least, the comparative study of titers in psoriatic patients and healthy subjects does not suggest an impairment in rubella antibody synthesi