The responses of various age-groups of psoriatic patients to a four-week period of climatotherapy at the Dead-Sea was compared in three separate studies. In the first study, plaque clearance following climatotherapy was evaluated in a group of 688 psoriatics, as a function of age, sex and duration of the disease. Neither the age of the patient when treated, nor the duration of the disease, appeared to influence the degree of plaque clearance. However, when the age at onset of the disease was evaluated as the comparative parameter-a decrease in the rate of response with increasing patients' age was recorded. In the second study, the type and incidence of side effects after climatotherapy was studied in 502 patients aged over 65, and in more than 4,500 younger psoriatics. There was no difference in the type and frequency of side effects between the two age-groups. The most frequent side effects were: slight sun burn (8.2%), sun allergy (5.0%), common cold (3.4%), leg oedema (2.0%), diarrhea (1.4%) and herpes simplex (0.8%). In all cases the side-effects disappeared within a few days. In the third study, the reduction in the diastolic and systolic blood pressures in a group of 1,142 hypertensive psoriatics was evaluated as a function of time. It was demonstrated that while there was no significant age-dependent difference in lowering their diastolic blood pressure throughout the study, differences in lowering systolic measurements between the younger (< 40 y) and older (> 65 y) hypertensive patients were highly significant. On the basis of these studies we conclude that psoriatics aged 65 and over benefit from climatotherapy at the Dead-Sea no less than younger patients, and that, irrespective of age, high blood pressure is not a contraindication for this treatment in psoriatic patients at the Dead-Sea.