Other tissue involvement has been described in Darier's disease, eg: susceptibility to infection. In order to know if this susceptibility is due to abnormal phagocytosis and if this can revert by administration of retinoic acid (RA), blood monocyte-derived macrophages, from four individuals with Darier's disease were obtained prior and after administration of RA to determine in them morphological, cytochemical and phagocytic activity changes. It was observed that phagocytosis was diminished and RA administration increased it, without changes in enzyme distribution. This modification of phagocytosis could be due to a reordenation of cytoskeleton.