Objective: This study aimed to conduct a clinical test of the reliability of the OHAQ questionnaire in the general population. This study aimed to assess oral hygiene activities in the general population using the OHAQ questionnaire. Additionally, we evaluated the clinical status of participants from the general population. Furthermore, the study aimed to compare the assessments of participants' oral hygiene activities obtained through the questionnaire with their clinical status. Reliability of the questionnaire was tested in the general population to identify individuals at risk of developing oral diseases and to determine participants' needs for dental care. Material and Methods: A cross-sectional study was conducted from the beginning of June to the end of August 2024 on 80 participants from the general population. The research was based on the OHAQ questionnaire. The survey questionnaire consisted of three parts. The first part contained questions related to general information about the participant and general information about oral health. The second part consisted of the Oral Health Activities Questionnaire (OHAQ). The third part of the questionnaire included a form for the clinical examination, which dentists completed during their clinical examination. Ethics Committee of the Faculty of Medicine in Split approved the study. Results: The study included 80 participants, of which 19 (23.8%) were men and 61 (76.2%) were women. The average age of the participants was 38 years (age range from 19 to 77). The majority of participants use fluoride toothpaste and change their toothbrush every three months. Additionally, they visit their chosen dental doctor twice a year. Participants almost never skip brushing their teeth in the evening, and a certain number of them use dental floss at least once a day, though they rarely use floss more than once a day. Conclusion: Given the overall values of the OHAQ questionnaire, participants demonstrated a high level of oral hygiene activities. There was no significant association between most of the oral hygiene activity indicators obtained from the questionnaire and the oral health indicators determined by clinical examination, except for plaque levels and the regularity of dental visits, as well as basic oral hygiene activities (BOHA). The study showed a significant correlation between better oral hygiene habits and lower levels of dental plaque. Future research should include a larger and more representative sample. Additionally, further efforts are needed, including the validation of potential additional questions and the development of a shorter and faster questionnaire, which would be a useful tool for quick screening in clinical practice as well as a public health issue at the general population level.