We provide evidence on the relationship between four different aspects of financial literacy: Financial knowledge, attitudes towards money, self-efficacy, and financial behavior. Ninth-grade high school students (N = 2.025) in 22 schools and in four different educational tracks in the western part of the Netherlands took part in the survey. A multilevel analysis at school and individual level was applied. Findings show that financial behavior is highly associated with attitudes towards money as well as financial knowledge. Attitudes towards money, in turn, are associated with financial behavior and financial knowledge. Furthermore, financial knowledge is related to attitudes towards money and financial behavior. In order to improve financial behavior among high-school students, financial education programs should have a holistic approach and address all aspects of financial literacy.