〔Objective〕This study aimed to determine whether the metacognition of intermediate nurses （5−19 years of experience） working in acute-care hospital settings influenced their content plateau.

〔Method〕A web-based questionnaire was administered at six facilities, while 163 responses were obtained. Multiple regression analysis （forced-entry method） was conducted with basic attributes and the subscales of the Adult Metacognitive Scale （AMS） as independent variables and the Content Plateauing Scale as the dependent variable.

〔Results〕The multiple regression analysis revealed that total AMS scores （β=-.27） and those for the subscale metacognitive knowledge （β=-.60） were significantly linked with participants’ content plateau.

〔Conclusions〕Among the independent variables, total AMS scores and those for the subscale metacognitive knowledge had a significant impact on participants’ content plateau. These results suggest that metacognition and metacognitive knowledge are crucial in overcoming the content plateau.

〔Objective〕To identify the difficulties new nurses with or tendencies toward developmental disabilities face in performing their duties, based on stakeholder perceptions.

〔Method〕Semi-structured interviews were conducted with four nurses with 2–4 years of clinical experience who had developmental disabilities or tendencies toward them. The interview data were examined using qualitative descriptive analysis.

〔Results〕Ten core categories were identified as difficulties for new nurses with or tendencies toward developmental disabilities in performing their duties: “uncoordinated behavior,” “insufficient retention of working memory,” “inability to self-regulate emotions,” “false self-interpretation and self-centered priorities,” “forced assistance with insufficient confirmation,” “difficulty changing behavior,” “inexperience with nursing techniques,” “disappointment in not finding a solution,” “disconnect between ideal self and reality,” and “isolation from ward staff.”

〔Conclusions〕The perceptions nurses with or tendencies toward developmental disabilities have of their difficulties differ from the perceptions of their supporters’ perception of their difficulties, which may lead to prejudice and discrimination. Therefore, their supporters should have knowledge about developmental disabilities and make efforts to understand the subject.