Between 1965 and 1987 the authors studied the survival of 169 patients (130 females, 39 males) suffering from follicular thyroid cancer. It is established that the factors favorably influencing the course of the disease are as follows: age below 40 years, female sex, tumor location inside the thyroid capsule. Radical surgery does not affect the survival, though it prolongs the time to the onset of metastases. In women below 40 years of age, iodine treatment performed within 1.5 months following surgery does not increase the effectiveness; therefore, its routine application is not recommended. In case of local metastases associated with hindered swallowing or respiration, external beam radiotherapy is indicated. Hormone substitution ensuring TSH restriction results in improved prognosis.