The aim of this retrospective study on 52 operated medullary thyroid carcinoma (MTC) was to assess clinical and biochemical factors influencing survival without clinical recidive. There were 52% of familial cases. Mean age was 44 years (3 to 78 years) with 58% of women. The diagnostic was made prostoperatively in 38% of case (nodular specimen), when it was strongly suspected for 50% of patients before intervention (familial context, and/or preoperative Calcitonin (CT) levels, and/or mutation). The medial survival rate was 54 month (3 to 360 month). The absence of postoperative negativation of the CT (between 1 to 3 month) was meeting in 43% of case. Twenty one patients (42%) had presented one or several clinical relapse. At the end of the study, five patients were died in a postoperative time-limit of 22 to 110 month. The different parameters studed were: the sex, the age, the tumoral stage, the familial cases, the tum-oral size, the calcitonin levels normalisation in the three month postoperatively, and the local nodes extent. The 5-year survival rate was 90%, and the 10-year survival was 80%. The familial cases had a better pronostic than the sporadic (no death in the familial group versus 80% of 5-year survival rate in the sporadic cases). In univariate analysis, the good survival-factors without clinical recidive were: the stage I or II (p < 0,0001), the female sex (p = 0,02), the tumoral size under 10 mm (p < 0,02), the postoperative negativation of CT levels (p < 0, 0002), and the absence of cervical node extent (p < 0,0005). In multivariate analysis, only the postoperative negativation of CT-levels was a good survival-factor without clinical relapse (p < 0, 001).