Faculty concentrate on teaching nursing students about safe medication administration practices and on challenging them to develop skills for calculating drug dose and intravenous flow rate problems. In spite of these efforts, students make medication errors and little is known about the attributes of these errors. Therefore, this descriptive, retrospective, secondary analysis study examined the characteristics of medication errors made by nursing students during the administration phase of the medication use process as reported to the MEDMARX, a database operated by the United States Pharmacopeia through the Patient Safety Program. Fewer than 3% of 1,305 student-made medication errors occurring in the administration process resulted in patient harm. Most were omission errors, followed by errors of giving the wrong dose (amount) of a drug. The most prevalent cause of the errors was students' performance deficits, whereas inexperience and distractions were leading contributing factors. The antimicrobial therapeutic class of drugs and the 10 subcategories within this class were the most commonly reported medications involved. Insulin was the highest-frequency single medication reported. Overall, this study shows that students' administration errors may be more frequent than suspected. Faculty might consider curriculum revisions that incorporate medication use safety throughout each course in nursing major courses.