Background <p>Patient safety is a significant aspect of healthcare delivery. However, research on interventions for improving patient safety culture in nursing homes is scarce. This study evaluated the effectiveness of a low-fidelity Room of Horrors (RoH) simulation on the attitudes of nursing home staff toward patient safety with a three-month follow-up.</p> Methods <p>This pre-post-follow-up longitudinal interventional study encompassed five nursing homes in Berlin, Germany. An RoH training session, including error detection and structured debriefing, was offered to all the nursing staff. Attitudes toward patient safety were assessed before, immediately after, and three months after the intervention using the German short version of the Attitudes to Patient Safety Questionnaire (G-APSQ-short). Generalized linear models (GLMs) were used to analyze the data for time effects and the influence of professional experience and group size.</p> Results <p>A total of 123 participants completed the baseline survey, and 66 completed the three-month follow-up. There were minimal changes in the nursing staff’s attitude toward patient safety. However, modest correlations were observed between professional experience and changes in attitude and between group size and changes in attitude. Smaller groups had higher post-intervention scores, with the effect attenuating over time.</p> Conclusions <p>RoH simulations represent a feasible strategy for enhancing patient safety awareness among nursing home staff. However, sustained attitudinal change may require follow-up interventions and integration into more far-reaching patient safety programs.</p> Clinical trial number <p>Not applicable.</p>