This study identified situations indicating medication errors or near misses by analyzing medication orders and the nursing staff's performance. It also implemented a cycle of lectures and a course on safety in medication administration for professionals at the emergency room in a hospital in the northeastern region of Brazil. The results showed that of 1,585 orders under analysis, 83,9% did not clearly express the medication presentation and 84.6% did not define the dosage from prescribed medication, in 34.2%, the administration time was unchecked; in 22.5%, the time had been circled. Among the non-administered medication, 26% were antibiotics and anticoagulants and 15% analgesics. The professionals participated in the implemented strategies with good attendance levels.