Introduction: In an average Polish person aged 35–44, more than 16 teeth have or had been affected by dental caries. Of that number, almost half of the teeth have already been extracted. Oral health behaviours contribute to this civilization disease in 50%. Such poor oral health status limits the ability of the affected people to take many social and professional roles. Objectives: To evaluate current oral health behaviours and their trends among 35–44 year old Polish people during the period of recent 30 years. Material and Methods: The data were obtained from the International Collaborative Studies conducted in 1978 and 1988 at the Nofer Institute of Occupational Medicine, Łódź, Poland, under the auspices of the World Health Organization (WHO) as well as from 3 stages of the study on Nationwide Monitoring of Oral Health Status and Its Conditioning performed in 1998, 2002 and 2010. The researchers evaluated oral health behaviours and oral health condition of 5425 subjects. Results: Despite a noticeable improvement, poor oral health behaviours are observed in 30%–40% of the adults. In the analysed period, the number of people brushing their teeth at least twice a day increased by more than 10% and the number of people using dental floss increased by 38%. Only 60% of the adults visited a dentist at least once a year. Reduced accessibility of state-run, free-of-charge dental care has caused that over 58% of Poles paid for their dental services. Every 3rd person of working age has not visited a dentist for longer than 2.5 half years, primarily due to behavioural and financial reasons. Oral health behaviours of Polish people are among the poorest in Europe. Conclusions: Despite a noticeable improvement of the behaviours, gap between the Poles and citizens of other highly developed countries is around 20 years. A health promotion programme including oral health issues, if implemented in workplaces, might considerably reduce this gap.