Gross abnormalities of the mammary glands of 1650 culled ewes were recorded. Clinically obvious lesions were detected in 211 (12.8 per cent) of udders; 77 per cent of lesions were abscesses. A generalised calcification of the whole of a gland was observed in 23 udders. It is concluded that abnormalities of the udder are an important reason for the culling ewes. The assessment of the cost-effectiveness of measures to reduce the incidence of mastitis would be worthwhile.