Background: The relative efficacy of the addition of induction chemotherapy to chemoradiotherapy compared with chemoradiotherapy alone for patients with head and neck cancer is unclear. The PARADIGM study is a multicentre open-label phase 3 study comparing the use of docetaxel, cisplatin, and fluorouracil (TPF) induction chemotherapy followed by concurrent chemoradiotherapy with cisplatin-based concurrent chemoradiotherapy alone in patients with locally advanced head and neck cancer. Methods: Adult patients with previously untreated, non-metastatic, newly diagnosed head and neck cancer were eligible. Patients were eligible if their tumour was either unresectable or of low surgical curability on the basis of advanced tumour stage (3 or 4) or regional-node stage (2 or 3, except T1N2), or if they were a candidate for organ preservation. Patients were randomly assigned (in a 1:1 ratio) to receive either induction chemotherapy with three cycles of TPF followed by concurrent chemoradiotherapy with either docetaxel or carboplatin or concurrent chemoradiotherapy alone with two cycles of bolus cisplatin. A computer-generated randomisation schedule using minimisation was prepared and the treatment assignment was done centrally at one of the study sites. Patients, study staff, and investigators were not masked to group assignment. Stratification factors were WHO performance status, primary disease site, and stage. The primary endpoint was overall survival. Analysis was by intention to treat. Patient accrual was terminated in December, 2008, because of slow enrolment. The trial is registered with ClinicalTrials.gov, number NCT00095875. Findings: Between Aug 24, 2004, and Dec 29, 2008, we enrolled 145 patients across 16 sites. After a median follow-up of 49 months (IQR 39-63), 41 patients had died-20 in the induction chemotherapy followed by chemoradiotherapy group and 21 in the chemoradiotherapy alone group. 3-year overall survival was 73% (95% CI 60-82) in the induction therapy followed by chemoradiotherapy group and 78% (66-86) in the chemoradiotherapy alone group (hazard ratio 1·09, 95% CI 0·59-2·03; p=0·77). More patients had febrile neutropenia in the induction chemotherapy followed by chemoradiotherapy group (16 patients) than in the chemoradiotherapy alone group (one patient). Interpretation: Although survival results were good in both groups there was no difference noted between those patients treated with induction chemotherapy followed by chemoradiotherapy and those who received chemoradiotherapy alone. We cannot rule out the possibility of a difference in survival going undetected due to early termination of the trial. Clinicians should still use their best judgment, based on the available data, in the decision of how to best treat patients. The addition of induction chemotherapy remains an appropriate approach for advanced disease with high risk for local or distant failure. Funding: Sanofi-Aventis.