Background: The effectiveness of sustainable healthcare education in improving nursing students' knowledge and attitudes has been demonstrated through short-term studies with pre-post test design. However, there is a need to study long-term retention of students' knowledge and attitudes, also their skills in achieving sustainable healthcare from the use to disposal of healthcare resources by providing a hands-on learning experience via simulation. Aim: This study investigated the effects of sustainable healthcare education using cooperative simulation on nursing baccalaureate students' sustainable nursing knowledge, attitude and skills by comparing the self-directed learning. Design: This randomized controlled experimental study with pre-post-follow up design was registered under ClinicalTrials.gov with number NCT05504421. Settings: The study was conducted at a nursing faculty in a state university. Participants: The study sample comprised 70 third grade nursing students. Methods: Following narrative-based lectures explaining sustainability in nursing, students were randomly assigned to two study groups; an intervention group using cooperative learning-based NurSusToolkit Project cases and the control group using self-directed learning throughout 4 consecutive weeks. Both groups then performed a high-fidelity simulation practice focusing on sustainable healthcare. Data were collected using the Sustainability Attitudes in Nursing Survey, Sustainable Healthcare Knowledge Form, Skill Checklist and Debriefing Form. Quantitative data were analyzed using t-tests, Friedman test, Fisher's Exact test, intraclass correlation coefficients and Cohen Kappa calculations in IBM SPSS Statistics version 23 software. Qualitative data were analyzed via an inductive approach. Ethical approval and official permission were obtained. The students completed informed consent forms. Results: In the post-test, no significant differences were determined between the groups in terms of sustainable nursing knowledge (U = 557.5, p = 0.503), motivation (U = 514.5, p = 0.237) and attitudes (U = 610, p = 0.976). In the follow-up test, the sustainable nursing knowledge (U = 221.500), motivation (U = 282.500) and attitudes (U = 191) were significantly higher in the intervention group (p < 0.001). In the simulation practice, the intervention group had higher rates of correct separation of nursing care-related waste (intervention group = 77.77 % for both observers, the control group was 0 % and 11.11 % for observer 1 and 2, respectively, Cohen Kappa = 0.898, p < 0.001). In the debriefing, the intervention group requested more simulation practices (33.33 %) to acquire sustainable nursing skills, while the control group did not. Conclusions: Sustainable healthcare education using cooperative simulation that has long-term effects can enable future nurses to lead the shift towards climate-smart and sustainable nursing care.