Objectives: to identify, classify, and analyze modes of failure in the medication process. Methods: evaluative research that used the Healthcare Failure Mode and Effect Analysis (HFMEA) in a service of bone marrow transplant from June to September 2018, with the participation of 35 health workers. Results: 207 modes of failure were identified and classified as mistakes in verification (14%), scheduling (25.6%), administration (29%), dilution (16.4%), prescription (2.4%), and identification (12.6%).The analysis of risk showed a moderate (51.7%) and high (30.9%) need of intervention, leading to the creation of an internal quality assurance group and of continued education activities. Conclusions: the Healthcare Failure Mode and Effect Analysis showed itself to be a tool to actively identify, classify, and analyze failures in the process of medication, contributing for the proposal of actions aimed at patient safety.