In three generations of a family investigation for coexpression of May- Hegglin anomaly and hereditary nephritis was done by routine studies, as well as electron microscopy of renal tissue and blood cells, platelet aggregation studies, audiograms, and ophthalmologic evaluations. The propositus had typical May-Hegglin anomaly and a mild form of hereditary nephritis. One son had May-Hegglin anomaly and possible hereditary nephritis, and one daughter had May-Hegglin anomaly and probable hereditary nephritis. A grandson had May-Hegglin anomaly but no evidence of hereditary nephritis at age 23. The mild form of hereditary nephritis described here was atypical for Alport's syndrome, but together with similar reports, suggests that a combination of May-Hegglin anomaly and mild hereditary nephritis may be a distinct disorder.