Fluorotic lesions have been studied in cows and calves of SRB breed on farms belonging to 2 agricultural companies. From the one company (HP) in Dalecarlia 3 calves, 4 heifers and 2 cows were examined and from the other (B) in Sodermanland 12 bull-calves. The submitted material consisted of a carcase from 1 dead calf and skull, metacarpus and in some cases kidneys from slaughtered animals. The fluorine content of feed and water samples was determined. In material from HP extensive enamel defects and strong wear were found in the deciduous incisors. Fluorotic lesions in calves have not been described previously. One calf had strong osteoporosis and in the rest of the material osteosclerosis and subperiosteal bone apposition was found. In the kidneys some tubular atrophy was found. Kidney lesions have not been observed previously in bovine fluorosis. Dark furrows and enamel defects appeared in the teeth of the heifers and the cows. In the skeleton they had osteosclerosis and in some cases also subperiosteal bone appositions. The fluorine content of the skeleton varied between 500 and 3,100 p.p.m. in bone ash. Water samples contained 0.5–2.0 and the mineral supply 500–630 p.p.m. of fluorine. In material from company B widespread enamel defects, strong wear of the deciduous incisors and deviations and irregular eruption of the permanent incisors were found. In the skeleton osteosclerosis and subperiosteal bone apposition and in the kidneys in 1 case patchy atrophy of the tubules were found. Microscopically the skeleton showed signs of repair. The fluorine content of the skeleton varied between 135 and 300 p.p.m. in the ash. In water samples 1.5–4.0 p.p.m. of fluorine were found. The used mineral supply contained 300–500 p.p.m. of fluorine. The fluorosis in these animals was considered to be caused by a combination of the fluorine of the water and the mineral supplement. Considering the microscopic picture and the low skeletal fluorine level, the lesions in the bull-calves of company B were interpreted as fluorosis being in a process of repair. To this view contributed the fact that the ingested fluorine in these animals was reduced during the fattening period.