The objective of this paper is to present the key findings on the exploration of safety culture of bus drivers in Norway and Greece. An empirical study was conducted to examine whether and how membership in different socio-cultural units influences transport safety behaviour and outcomes in professional transport. Qualitative interviews with bus drivers in Norway and Greece were conducted, followed by a survey among 228 bus drivers in Norway and Greece. Our study provides four main results. First, bus drivers in Greece report of more aggressive violations in traffic than Norwegian bus drivers. Second, aggressive violations are predicted by national transport safety culture, specified as descriptive norms (“violations”) and values (individual freedom to take risk in traffic). Third, respondents’ aggressive violations in traffic predicted their accident involvement, although “work related variables” were more strongly correlated. Fourth, organizational safety culture contributes negatively to aggressive transport safety behaviours, meaning that a positive organizational safety culture may reduce (the negative impact of national transport safety culture on) aggressive violations in traffic. Although more research definitely is needed, our study indicates a relationship between national transport safety culture, transport safety behaviour and accident involvement, that perhaps could be developed further to shed light on national transport safety records.