A patient is described with both polymorphous light eruption (PLE) and aquagenic urticaria appearing at 29 yr of age. Her father had the same symptoms after exposure to solar irradiation or water. Four to 6 h after 5-15 min sun-exposure, both had symptoms of general malaise and swelling of various joints. The skin symptoms in our patient were initially urticarial and later mainly papular and vesicular. They were elicited by irradiation with low doses of 300-360 nm and also appeared after 400 and 500 nm. Window glass offered little protection. PUVA treatment improved both conditions remarkably.