Nijmegen breakage syndrome (NBS) is a rare DNA repair disorder caused by mutations in the NBS-1 gene (8q21). Patients with this autosomal recessive condition have characteristic facial features, microcephaly present at birth, immunodeficiency, predisposition to malignancy, ionizing radiation hypersensitivity, and growth retardation. We report a 12-year-old boy with NBS associated with porokeratosis; to our knowledge this association has not previously been reported.