Patients in intensive care units (ICUs) are more likely to experience dangerous events because their conditions and treatments are so complicated. A strong culture of patient safety is linked to fewer difficulties and bad occurrences for patients. The objective of this research was to assess the impact of an educational program aimed at empowering nurses and supervisors on the patient safety culture inside adult critical care units. Six adult critical care units at Namazi Hospital in Shiraz, Iran, took part in a randomized controlled experiment from April to September 2015. We utilized a census and proportionate stratified selection to randomly determine 60 nurses and 20 supervisors to participate in the experimental and control groups. The intervention included a two-day training, posters, and brochures on themes including patient safety, the culture of patient safety, how to communicate safety concerns, and Team Strategies and Tools to Enhance Performance and Patient Safety. A hospital survey on patient safety culture was used to gather data. In the end, 61 people finished the experiment. We employed chi-square analysis, independent-samples t-test, paired-samples t-test, and descriptive statistics to look at the data. P values less than 0.05 were deemed statistically significant. The experimental group's average score for patient safety culture was much higher than the control group's after the test (2.84 ± 0.37, P < 0.001) (3.46 ± 0.26). It also did better than the pretest score of 2.91 ± 0.4 (P < 0.001). Moreover, five of the twelve sites showed substantial alterations in the experimental group. But there was no clear change in areas like the number of reported occurrences and how people reacted to mistakes without punishment.