The study aimed to develop a validated measure of the 5C psychological antecedents of vaccination, which includes confidence, complacency, constraints, calculation, and collective responsibility. Existing measures primarily focus on confidence, but empirical and theoretical work suggests that these other factors also play a role in explaining vaccination behavior. Three cross-sectional studies were conducted to develop and validate the 5C scale. Study 1 used factor analysis to develop an initial scale and assess its validity (N = 1,445). Study 2 refined the scale and tested its content and construct validity (N = 1,003). Study 3 compared the 5C scale with six existing measures of vaccine hesitancy (N = 350). The results led to the development of a long (15-item) and short (5-item) 5C scale, which was found to be reliable and valid indicators of the 5C antecedents of vaccination. The 5C scale provides a novel tool to monitor psychological antecedents of vaccination and facilitates diagnosis, intervention design, and evaluation. The short version is suitable for field settings and regular global monitoring.The study aimed to develop a validated measure of the 5C psychological antecedents of vaccination, which includes confidence, complacency, constraints, calculation, and collective responsibility. Existing measures primarily focus on confidence, but empirical and theoretical work suggests that these other factors also play a role in explaining vaccination behavior. Three cross-sectional studies were conducted to develop and validate the 5C scale. Study 1 used factor analysis to develop an initial scale and assess its validity (N = 1,445). Study 2 refined the scale and tested its content and construct validity (N = 1,003). Study 3 compared the 5C scale with six existing measures of vaccine hesitancy (N = 350). The results led to the development of a long (15-item) and short (5-item) 5C scale, which was found to be reliable and valid indicators of the 5C antecedents of vaccination. The 5C scale provides a novel tool to monitor psychological antecedents of vaccination and facilitates diagnosis, intervention design, and evaluation. The short version is suitable for field settings and regular global monitoring.