OBJECTIVE The purpose of this study is to characterize head and neck squamous cell carcinoma (HNSCC) in the Puerto Rican population. This is a follow-up to our initial published report on the first 134 patients. Specifically, demographic characteristics, stage at presentation, initial treatment given, and rate of recurrence were studied. METHODS Relevant data was obtained from 445 histologically confirmed HNSCC cases identified through the University of Puerto Rico School of Medicine Otolaryngology Department Head and Neck Cancer Clinics between August 1993 and January 2003. Data collected after informed consent included demographic factors (sex, age, areas of residence, income); risk factors (occupation, alcohol intake, cigarette usage); and pathological variables (tumor location, histopathology, stage at presentation, current disease status, tumor recurrence). RESULTS The average age at diagnosis was 64.0 years (range 18-98); 84.5% of the patients were male, 16% were females. The most frequent anatomical sites of the primary tumor were the larynx (36.4%) and the oral cavity (29.9%). The majority of patients (61.1%) presented with advanced stage (III-IV) disease at the time of diagnosis and over half (55.5%) had moderately-differentiated tumors. Most patients had less than 12 years of formal education (81.2%). Prolonged use of tobacco and alcohol identified in 88.1% and 79.8% of patients, respectively. The most frequent therapeutic modality used was radiation therapy followed by the combination of radiation and surgery. Twenty five percent of the cases experienced a recurrence of disease during the follow-up period. CONCLUSIONS These findings emphasize the need for early detection programs for HNSCC in Puerto Rican patients given the high rate of advanced-stage disease at time of diagnosis. The key role of heavy alcohol intake and tobacco use as risk factors in the development of HNSCC is once again highlighted.