BACKGROUND Eye and mouth dryness are the most common symptoms reported during ophthalmological and dental examinations, and their frequency increases with age. In connection with population aging and the huge variety of factors and conditions that can induce this condition, it is becoming a serious and growing problem. The purpose of the present study was to determine whether ocular dryness and concomitant xerostomia is associated with particular systemic diseases. MATERIAL AND METHODS We enrolled 642 non-Sjögren patients referred for examination to the ophthalmology or dental clinic of Lublin region, Poland. The research was conducted using a standardized interview: The Interview and Examination Questionnaire. All patients responded to the survey questions, which concerned systemic diseases, lifestyle, with special emphasis on computer work, spending time in polluted and air-conditioned rooms, and subsequent questions about the subjective symptoms of ocular and mouth dryness. RESULTS There were 424 patients who presented signs and symptoms of both ocular and mouth dryness. Our study showed a statistically significant association between this condition and the age and sex of the patients and systemic diseases such as hypertension (p=0.0000), cardiovascular disease (p=0.057), and stress (p=0.036), and time spent at the computer (p=0.00015). CONCLUSIONS Ocular dryness and concomitant xerostomia may occur in apparently healthy individuals, but is more frequent in patients with systemic disorders. The lack of dry eye and dry mouth symptoms does not exclude insufficient tearing and salivation; thus, the disorders are usually underestimated. Our study indicates that ocular and mouth dryness are the most common conditions seen in out-patients, due to increased use of medications, computers, and air conditioning.