BACKGROUND: Lymphangioleiomyomatosis (LAM) is a rare and progressive disease of young women with no effective treatment. Previous estimates of 10 year survival, based mostly on case series or patients from tertiary centres, have ranged from 40% to 79%; no data are available on the progression of respiratory disability. In order to provide data for patients and for planning intervention studies, we have looked at the time course of LAM using a national cohort. METHODS: Time to death, time to MRC dyspnoea grades 2-5, and need for oxygen in patients on the UK LAM database were analysed using Kaplan-Meier analysis and Cox regression. RESULTS: Fifty seven of 72 patients responded with a median duration of follow up of 12.6 years (range 2.3-37) from the onset of symptoms. Ten year survival was 91% from onset of symptoms but varied widely with 11 patients alive after 20 years. Median time to MRC grade 3 dyspnoea (breathless walking on the flat) was 9.3 years (95% CI 5.1 to 13.4) from onset of symptoms. CONCLUSIONS: Survival from LAM appears to be better than that reported in early studies. These data should be helpful for patients and for planning clinical trials.