The aim of the study was to evaluate the impact of the oral health on Oral Health Related Quality of Life (OHRQoL) among patients looking for dental treatment at the Department of Periodontology, dental prophylaxis and oral pathology in University Dental Clinic (UDC) in Kraków. 250 adult patients were involved in a cross-sectional study consist of intraoral clinical examination and a questionnaire survey. There was a statistically significant negative correlation between self-assessment of OHRQoL and OHIP-14 in relation to teeth, oral mucosa and dentures. OHRQoL in patients complaining about caries was lower than in patients without these complaints. Among patients seeking prosthetic treatment their self-assessment of OHRQoL was worse than patients without these needs. Self-assessment of OHRQoL in patients visiting the clinic for follow-up visit was better compare to patients looking for treatment. There was a negative and statistically significant correlation between OHRQoL and 1) DMFT index, 2) number of decayed teeth and 3) number of missing teeth. The main aim for health care providers in dentistry should remain prophylaxis to maintain as many as possible healthy teeth in patients. Regular visits at the dental office seem to influence less patients’ well-being.