Background: Birt-Hogg-Dube syndrome (BHDS) is an autosomal dominant disease characterized by hair follicle hamartomas, kidney tumors, and spontaneous pneumothorax; its cause is a heterozygous mutation in the FLCN gene. Colorectal polyps and carcinoma have also been reported in BHDS. FLCN mutations can be detected in patients with isolated primary spontaneous pneumothorax (PSP), so PSP may present as part of BHDS. The aim of this report is to enhance awareness that patients presenting with spontaneous PSP should be evaluated for FLCN mutations. Materials and Methods: A 44-year-old woman with PSP and her parents were analyzed for FLCN mutations. One of the patient's paternal aunts had a PSP and two of her paternal aunts had colon cancer diagnosed at early ages. Results: A novel in-frame deletion in the FLCN gene, c.932_933delCT (P311Rfs*78), was detected in the proband and in her unaffected father. Conclusions: We recommend that molecular analysis of the FLCN gene be performed in patients with PSP and their families, and that mutation carriers be examined for kidney and colon tumors.