Purpose of this study was to investigate and compare differences in oral health awareness between Croatian and Italian urban adolescents. The sample consisted of primary school last grade students aged between 13 and 15 years, 300 children from Zagreb (Croatia) and 298 children from Bari (Italy). Oral health awareness was evaluated using a self-administered standardized questionnaire. Self-perception of oral health proved to be different between the two groups (p < 0.001). The Croatians reported that their oral health was "excellent" or "very-good" more often than the Italians (68.6% vs. 50.2%). The reasons given for visiting a dentist were different (p < 0.001). The Italians cleaned their teeth more often than the Croatians ("two or more times a day", 83.1% vs. 72.2%, p < 0.003). Wooden toothpicks were preferred by the Croatians (p < 0.001), while floss was preferred by the Italians (p = 0.03). The awareness regarding the use of fluoridated toothpaste was higher in the Italian group (95.6% vs. 72.5%, p < 0.001). The Croatians were consuming sweetened foods more often than the Italians (p < 0.001). Croatian adolescents reported more indicators of a lower level of oral health awareness than the Italians, while on the contrary Croatians had higher esteem of their oral health. Defining national preventive strategies is essential for improving adolescents' attitudes toward oral health in both countries, particularly in Croatia.