The purpose of this study is to assess the level of moral development, spiritual intelligence, and critical thinking of nurses, and to see if there is a relationship between these constructs for them. A descriptive correlational design was used, with a sample of 102 nurses in Iran. The descriptive statistics and Pearson’s correlation were done on the survey results using SPSS (Version 24). The moral development level scores of the nurses were 34 ± 2.17, which is considered average, critical thinking was 25 ± 1.23, which is considered relatively high, and spiritual intelligence scores were 41 ± 2.75, which is considered relatively low. Both spiritual intelligence and critical thinking were positively correlated with the nurses’ moral development (
