At the beginning of 2020, the COVID-19 pandemic took place worldwide, which had an impact and consequences on almost all areas of life. In addition to the pandemic, Croatia was hit by two stronger earthquakes in 2020, which were felt in most parts of the country. Many people, including students, felt fear and / or frustration because of the new situation, which could result in increased levels of stress and consequently affect changes in the use of addictive substances. This research paper was created with the aim of gaining insight into the frequency, habits, and changes in the consumption of addictive substances by Croatian students during the COVID-19 pandemic. The survey was conducted in May of 2021 using an online questionnaire that was distributed using the "snowball" method. The sample consists of 444 participants, of whom 60.4% are female students. The results indicate that male students consumed addictive substances more frequently than female students. Age did not affect differences in cravings, while it effected consumption as older students used tobacco products more frequently than younger ones. Considering the perceived changes in the frequency of consumption of certain addictive substances, it was found that there was a significant increase in cannabis use among male students. As the most common reasons for reduction of substance use during the pandemic, students reported self-growth and personal development, unavailability of addictive substances due to closed catering facilities and loss of motivation to use. The main reasons for the increase of substance use were boredom, more pronounced symptoms of anxiety, excess free time, and more pronounced symptoms of depression. Substances were most often used with peers in person.