Medication errors not only harm patients and increase hospital length of stay, but they are also an economic burden to patients and the health system. This study describes the types of medication errors and related costs in a Brazilian adult intensive care unit (ICU). The most common error type was omission, accounting for half of all errors. Scheduling and prescription errors were significantly correlated with increased hospitalization costs. Additionally, some medication doses contained more than one error type, driving up costs even further.