204 patients with Hodgkin's disease not previously treated were given vincristine, chlormethine, procarbazine and prednisone (protocol H2-65) for six months, followed by monthly vinblastine injections. Additional prophylactic radiotherapy was given to 50 non-randomised patients. Three-monthly reinduction treatment was administered to a further 50 patients during the year following the original induction cure, afterwards only every six months, and no treatment after four years. Among 109 patients in stage III complete remission occurred in 53% and partial (incomplete) remission in 36%. Among the 58 patients in stage IV, 21 had complete and one incomplete remission. Among 37 patients in stages I and II, 33 went into remission. The remission curves reached a plateau in the 42nd month in 74 plus or minus 6% of those in complete and 56 plus or minus 8% of those in incomplete remission (P less than 0.03). Increasing age had an unfavourable prognosis: the more progressed the anatomical stage the less favourable the prognosis. Surprisingly, stage IV (lymphocyte-poor) had a better prognosis on polychemotherapy than other histological forms. Signs of clinical activity did not influence prognosis, but biochemical signs of activity are unfavourable for remission duration (P less than 0.01). Patients who also had radiotherapy had longer remissions (P less than 0.01). Exacerbations occurred in 38, never beyond the 42nd month. Recurrence occurred in 21 of them in the dame lymphatic region as was affected at the beginning of the disease, while in the other 17 patients an extralymphatic episode occurred. There was a positive correlation between histological form and type of recurrence.