Characteristics of medication errors involving the intravenous (IV) route of administration were analyzed in reports from 1995 to 2013. This was accomplished through a voluntary medication error reporting program. A retrospective case study design analyzed reports by practitioners or consumers on IV-associated medication errors (N = 975) affecting patients. Patterns in error accounts reflected cultural changes in health care organizations. Equipment, labeling, incorrect route of administration, types of errors, patient outcomes, and causal agents represented major codes. Results point to health care provider and consumer knowledge, the need for ongoing education of nursing staff, and interdisciplinary strategies for preventing IV-associated medication errors.