One hundred fifty-nine patients with squamous-cell carcinoma of the oral cavity, oropharynx, nasopharynx, hypopharynx, and supraglottic larynx, and with clinically negative neck (Stage NO) were reviewed to determine the value of elective neck irradiation (ENI). The primary cancer was controlled in 125 patients; in these patients the neck failure rate was 1.9% with ENI and 18% without ENI. Recurrence in the neck in cases where the primary cancer was controlled was associated with an increased risk of death due to cancer. The primary cancer was not controlled in 34 patients; in these patients the neck failure rate was 25% with ENI and 67% without ENI. Ten of 11 patients in whom treatment failed both at the primary site and in the neck died of cancer despite attempts at surgical salvage. ENI may be associated with an increased risk of local failure in oral tongue lesions as a result of a decreased proportion of treatment given with interstitial therapy.