A 58-year-old man and his son presented with the clinical and histologic characteristics of porokeratosis plantaris, palmaris, et disseminata. Porokeratosis plantaris, palmaris, et disseminata also occurred in two other family members. Marked improvement was demonstrated with oral aromatic retinoid (Tigason) therapy. The differential diagnosis from the other types of porokeratosis is discussed. It is suggested that punctate porokeratosis is a form fruste of porokeratosis plantaris, palmaris, et disseminata.