Twenty eight patients with various dermatological conditions were treated orally with the new aromatic derivate of retinoic acid, Ro 10-9359. The initial average dose was 48,3 mg/day and the maintenance dose was 26,6 mg/day. Duration of treatment ranged between 3 to 6 months. Evolution of erythema, infiltration and hyperkeratosis showed changes statistically significant (p < 0,05) and excellent to good results were obtained in 23 out of the 28 treated patients. On the basis of this study it is concluded that Ro 10-9359 is a promising drug for the treatment of several skin diseases, specially ichthyosis, Darier's disease, oral lichen planus, erythrokeratoderma variabilis and psoriasis. No serious side effects were reported; dryness of the lips, scaling of palms and soles, pruritus and thinning of the skin were the most common. In no case treatment was discontinued due to side effects. Laboratory controls did not show deviations from the normal values.