Birt-Hogg-Dubé syndrome (BHD) is an autosomal dominant genetic disorder characterised by pulmonary cysts, fibrofolliculomas and renal tumours. The pulmonary cysts may lead to pneumothorax, and in cases of primary, spontaneous pneumothorax the syndrome should be excluded. The renal tumours are frequently malignant, but slow-growing. Screening and family assessment enable discovery of renal cancer at an early stage. The syndrome is underdiagnosed and little known.