Background: Medication errors represent a serious problem in the hospital setting and remain a challenge to navigate among hospitalized patients in all departments. Mistakes in medication administration are considered a significant issue that threatens a patient's safety and may increase their hospital stay, treatment costs, and mortality rate. Medication errors commonly committed by nurses may include medication preparation or administration errors, which are associated with the highest risk areas in nursing practice. Methodology: A pretest-posttest, quasi-experimental, the observational design was used. Convenience sampling was employed to include all intravenous medication errors committed by nurses in three ICUs of Jordan University Hospital (pretest: 236 errors and post-test: 68 errors, respectively). A designed incident report was used for data collection. Data collection was carried out simultaneously in the three ICUs during nurses' preparation and administration of intravenous medications over two months for pretest and posttest data (May and June 2018). A tailored evidenced-based educational program designed using Phillips's Manual of I. V. Therapeutics: Evidence-based Practice for Infusion Therapy was furnished to all registered nurses utilizing structured classroom lectures and on-the-job training; moreover, educational medals of common medications and illustration posters were used as additional reminders.Results and Conclusion: More than half of nurses were females and held bachelor's degrees. Half of the observed medication errors were identified in the surgical ICU. Intravenous medication errors observed during the day shift were significantly higher in number than those in the night shift. A significant reduction in the number of medication errors was noted after the implementation of a bundle of interventions (i.e., there was a reduction from 236 errors to 68 errors). Giving (1) an omeprazole push and then (2) administering vancomycin rapidly thereafter, followed by (3) administering omeprazole at the wrong time, were the three most observed medication errors in the ICUs. Most medication errors were not reported officially using incident reports. Based on the category of the intravenous medication error, ‘wrong medication rate' followed by ‘wrong medication time', and then ‘mixing the medication with another drug' were the most prominent errors noticed. The rate of reported medication errors was significantly higher after program implementation. An ongoing surveillance system is required to monitor intravenous medication errors and to know the causes to find a solution to further decrease them and their consequences. Also, all nurses should receive an intensive specialized evidence-based educational program about medication handling, utilizing clinical training, and frequent reminding.