Objective The aim of the paper is to search for approved drug information and to investigate the knowledge and behaviour of patients who administer drugs with a potential impact on the ability to drive a motor vehicle. Subjects and methods The list of medicinal products included in the analysis has been established by searching the Agency for Medicinal Products and Medical Devices of Croatia medicines database according to the criteria of the ATC Classification, the dispensing regimen, and the name of the medicine as of March 30, 2018. The research was conducted in the period from 1 July 2018 to 30 September 2018 at the pharmacy unit of Gradska ljekarna Zagreb (Zagreb City Pharmacy). It included 130 adults who are active road users as drivers of motor vehicles and who have prescriptions or are actively using at least one medicine that can impact their ability to drive motor vehicles. A questionnaire containing 19 questions was designed for the research, covering general information (gender, age, education level), information on road use, awareness of medicines used and respondents’ self-evaluation of the medicine's influence on their ability to drive a motor vehicle. The data were processed by descriptive statistics, with graphs and tables. Results The paper analyses the impact of 355 active ingredients in medicinal products on the market in the Republic of Croatia intended for chronic (including chronic intermittent) use in outpatient treatment of adults. Of the total number of analysed substances, 105 (29.6%) have no impact on the ability to drive motor vehicles or have negligible impact. 165 (46.5%) analysed active ingredients have poor impact on driving motor vehicles, 54 (15.2%) have moderate impact, and 31 (8.7%) have significant impact on driving motor vehicles. Based on the results of the research that included drivers who take medicines with potential impact on their ability to drive motor vehicles, we have established that the respondents are aware of the said potential; however, just half of the respondents have received the information about the medicine having the potential to impact their ability to drive from a healthcare professional, physician, or pharmacist. Only 20% of all respondents have modified their behaviour (frequency of driving motor vehicles, ways of taking their medicine). Conclusions Given the results, it can be concluded that patients underestimate the risks associated with medicines which can have an impact on their driving, and that it is extremely important to improve the communication between healthcare professionals and patients regarding the risks associated with taking these medicines. The pharmacist’s key role is to ensure safe and effective use of medicines; therefore, more emphasis in the daily work of pharmacists should be placed on the potential of medicinal products which have an impact on the patient’s ability to drive motor vehicles, as well as on providing clear and unambiguous recommendations on taking these medicinal products.