Expectations to Electronic Medical Record (EMR) systems in healthcare are high when it comes to reducing medication errors and increasing security in the medication process. Studies show that certain types of medication errors are eliminated when introducing EMRs; however, such systems also entail new types of errors. Based on a study in an orthopedic surgical ward in a medium-sized Danish hospital, we investigate what previous types of errors can be reduced by using the EMRs but also what new types of errors may appear. We zoom in on the process of medicine prescription and focus on what new types of errors appear in the interaction between the doctors and the technology. Identifying and understanding the nature of errors that emerge when doctors use EMRs may enable system developers and implementers to better manage implementation and maintenance of future EMR projects and accordingly set up appropriate strategies to prevent medication errors.