A parathyroid insufficiency, defined like a functional deficit sufficient to pull down calcemia underneath 75 mg/l and/or give clinical obvious disturbances of neuromuscular hyperexcitability, have been observed on 57 patients (2,7%). The risk as interested bilateral gestures (5,5%) with a maximum for total thyroïdectomies (17,7%), surgery for carcinoma (8,5%) and Basedow's illness (8,3%). Less than half the patients can stop their vitaminocalcical treatment, and before the sixth month. First prevention is respect of the frail glandules and their vascularisation, obliging a particular, precise and bloodness surgery. Finally the autotransplantation of parathyroid gland accidentally pulled off or deteriored seems to constitute an interesting contribution.