Introduction:
Squamous cell carcinoma (SCC) is the most common head and neck malignancy. Smoking, alcohol consumption, viral infections, exposure, oral hygiene, and dietary, genetic, and occupational factors are the most important etiologic factors. The aim of this study was determining the incidence of etiologic factors in head and neck SCC.
 Materials and Methods:
This is a cross-sectional survey study for the determination of the etiologic factors of head and neck squamous cell carcinoma over a five-year period in the Otolaryngology Department of the Imam Khomeini & Golestan hospitals in Ahwaz.
 Results:
176 patients, comprising 151(85.8%) men and 25(14.2%) women, were studied. Overall mean age was 67.2 years. 148 (84.1%) patients were smokers. prolong exposure to chemical  fertilizer in 101 (57.4%) patients, Sun exposure in 21 (11.9%) patients, Low socioeconomic status in 124 (70.5%) patients, poor oral hygiene in 128 (72.7%) patients, high intake of hot tea drinking in 84 (47.7%) patients and malignancies in family in 12 (6.8%) patients were the most frequent risk factors. 17 (9.6%) patients have had opioid addiction and HPV was positive in 7 (3.9%) patients by PCR.
 Conclusion:
According to this study, tobacco smoking was the most important etiologic factor and had a strong effect on risk of head and neck squamous cell carcinoma. Other factors are also important and need more research study.