A risk factor is anything that increases a person's chance of getting a disease such as cancer. Different cancers have different risk factors. For example, unprotected exposure to strong sunlight is a risk factor for skin cancer, and smoking is a risk factor for cancers of the lung, larynx, mouth, throat, esophagus, kidneys, bladder, and several other organs.

Although researchers have found several risk factors that make a person more likely to develop nasal cavity and paranasal sinus cancer, many people with these cancers have no known risk factors. Even if a patient has one or more risk factors, it is difficult to know whether that factor actually caused the cancer.

Occupational exposures: Scientists have found many occupational risk factors that make a person more likely to develop nasal cavity and paranasal sinus cancer. Most of these risk factors are associated with substances in the work environment that are inhaled. These include occupational exposure to dusts from wood, textiles, and leather and even perhaps flour. Other substances linked to this type of cancer are glues, formaldehyde, solvents used in furniture and shoe production, nickel and chromium dust, mustard gas, isopropyl ("rubbing") alcohol, and radium. Some have also suggested that air pollution in heavily polluted cities such as Mexico City may also be a risk factor. None of these risk factors is completely certain because these cancers are so uncommon.

Smoking: Smoking is a major risk factor for nasal cavity cancer.

Family history: Most people with nasal cavity and paranasal sinus cancer do not have any relatives with this disease. Family history does not seem to be a risk factor for these cancers.