Lymphangiomyomatosis is a rare disease which affects young women of childbearing age. Eight women with pulmonary LAM were treated with antiestrogen therapy and were monitored by blood estrogen measurements along with clinical hypoestrogenic symptoms. Treatment ranged from three to nine years. The response to therapy was evaluated by the clinical course, chest x-ray films, pulmonary function tests and overall long-term outcome. Three patients died of respiratory failure after three, five and nine years of treatment. Of the five patients remaining alive, respiratory function deteriorated in four cases, after a transient period of mild improvement lasting three years in two cases. The last patient appeared stable after three years of follow-up. Time course ranged from 4 to 17 years. However, without a control group, we cannot determine whether or not the apparent improvement of the natural time course was due to the hormonal treatment.