Given the importance of the professional accountant in business relations in the business context, it is relevant to observe the moral and ethical behavior of these professionals in their relations with their peers. The study aimed to analyze as the main infrastructures committed by accountants registered with the Regional Accounting Council of the State of Mato Grosso (CRC-MT) and as penalties applied to them in the period from 2015 to 2018. In relation to the approach adopted in a research characterized- whether as a survey. The population consists of accountants registered in the council who have been prosecuted and penalized, in the period between 2015 and 2018. Data collection was carried out through the CRC-MT information portal, between the months of August and October of 2019. The results show a total of 1,304 infractions committed, with irregular Decore (Proof of Income Perception Statement) representing 23.54% of the total. As for penalties, fines and private warnings stood out the most. It should be noted, however, that a process for infraction can result in more than one decision, corresponding to an ethical and disciplinary penalty (a fine and a private warning).