Purpose: A study was conducted to clarify the relationship between the following factors concerning knowledge about radiation: the educational background of nurses; variable levels of knowledge of radiation resulting from differences in nursing duties and nursing experience; nurses’ self-evaluation of knowledge concerning radiation and anxiety about radiation exposure. Methods: All nurses of A hospital participated in a cross-sectional survey. Result: Three hundred and ninety-five (395) respondents completed the survey. The χ² test was used to examine items concerning whether or not nurses had received education concerning radiation. Significant correlations were found between the following two items: knowledge about radiation and self-evaluation of knowledge. More than 60% of the nurses had received education concerning radiation. The self-evaluation score was higher for the group who had graduated from nurse training institutes before 1988 (especially for the group aged 50 years and above) and for the group who had had experience working in a radiation clinic. Also, a correlation was found between the “self-evaluation score” and “knowledge score” (Pearson r＝0.42, N＝395, p＝0.001). Concerning the eight items related to nursing and duties in radiation care, the χ² test was conducted to examine the relationship between the presence or absence of nursing duties and experience in radiation care and anxiety about radiation exposure. The results showed that only one item was statistically relevant, “entering the radiation treatment room” (χ²＝8.754, df＝1, p＝0.003). Conclusion: Those nurses who had the most educational experience in radiation had the highest level of knowledge concerning radiation. Anxiety of exposure in nurses is reduced if there is work experience.