Résumé : The authors show the noteworthy efficacy of the aromatic retinoid Ro 10-9359 in the treatment of ichthyosis linearis circumflexa. The initial dose was 1 mg/kg daily; later on, the maintenance dose was 0.3 mg/kg daily. Ultrastructurally, transitional cells were observed between the granular and the horny layer. After treatment, large perinuclear pseudovacuoles appeared, as well as numerous microvilli.