Two patients had trichothiodystrophy but did not exhibit the commonly associated findings such as mental retardation, increased sensitivity to sunlight, ichthyosis, decreased fertility in males, and short stature. One of the patients had a transient combined immunodeficiency syndrome in early childhood lasting four years, but has remained in good health untreated for four years. The association of these two rare findings in this patient should alert us to the possibility that others with trichothiodystrophy may exhibit immunodeficiency.