Two hundred and two patients with clinically typical or biopsy-confirmed vulval lichen sclerosus were reviewed either at consultation (75%) or by retrospectively examining their chart. At diagnosis, 79% were 50 years or older. Ninety-six per cent complained of itching, pain and/or dyspareunia. Lichen sclerosus most often affected the labia minora and perineum but 50% had perianal and 13% had extragenital disease. Thirty-five patients gave a history of psoriasis (17%), which affected the vulval area in 10. Thyroid disease was reported in 39 patients (19%), and 33 gave a family history of thyroid disease. Of those tested (142), 20% had elevated thyroid antibodies. Topical clobetasol propionate was very effective but at least intermittent treatment was required long term in 85%. At follow up, 101 of 185 patients (56%) were asymptomatic but 22 (12%) continued to have moderate-to-severe symptoms. Thyroid disease and psoriasis are common associated conditions.