This research has a quantitative focus and is descriptive. It was applied to internal auditors and collaborating technical personnel from 22 governmental internal auditing units. This research is comprised of a 44-question questionnaire divided in the three variables that underpin it: the methodology of the internal auditing units for assuring quality; the application of the normative framework and practical improvements; and the strengths and weaknesses of the internal auditing units. The results show that the internal audits are made up of personnel who meet the academic and experience requirements. However, work quality must be improved, by implementing recommendations such as the measurement and analysis of key performance indicators, the inclusion of operational audits in the annual work plan, the implementation of global best practices, the use of technological tools, the identification of risks, the introduction of a quality management system, continuous professional capacity developments, etc.