After a review of the historical background and the first studies with fluoride therapy for osteoporosis the author presents his own studies of more than 100 cases of industrial fluorosis. It is followed by instructions how to perform the fluoride therapy: indications, contra-indications, dosage, controls and additional therapy. Since 1969 we treated 158 patients suffering from primary and secondary osteoporosis with 3 different sodium fluoride preparations (pure sodium fluoride powder, Ossin, Koreberon). Clinically and subjectively, 80.4% recovered or became symptom-free. In 53.8% (with Koreberon in 64%), we detected radiologically distinct reossification in the spine after 23 +/- 12 months, in a further 26.6% the reossification was questionable and only 4.4% showed further fractures. In summary, we found about 20% of fast-responders (reossification after 13.2 months, high alkaline phosphatase), 60% of responders and 20% of non-responders. The strengthening effect of the sodium fluoride therapy becomes especially evident if considering the spontaneous fracture rate. Side effects were: gastrointestinal disturbances (34%), gastric ulcers (4.4%), stress fractures (6.9%), very common arthralgies (34%), and sometimes overdosages (fluorosis). Only if therapy is controlled most intensively will the greatest effectiveness be obtained.