Plants of the family Umbelliferae are known to cause a phytophotodermatitis due to a phototoxic reaction caused by furocoumarin (psoralens) and simultaneous exposure to sunlight. We report four patients with partial skin thickness burns, induced by this phototoxic reaction. One occurred after contact with parsley (Apium petroselinum) and three others after contact with giant hogweed (Heracleum mantegazzianum) and simultaneous exposure to sunlight.