background: in brazil, resolution 196/96 and its amendments regulate the preservation of rights, respect and dignity of human beings involved in research. objective: to analyze the adequacy of free communications (fc) presented during the xviii congresso pernambucano de cardiologia to resolution 196/96. methods: during a cross-sectional study, interviews were carried out with the authors of the fc presented at the congress and the abstracts of the studies were assessed in order to identify the need for previous approval by a research ethics committee (rec). results: a total of 90 fc were presented and, in most of them (86.8%), medical files were the most commonly used source of data. only 23.1% of the fc were submitted to the assessment of a rec and 15.4% of them used a free and informed consent form (ficf). among the authors whose studies were not assessed by a rec, 65.6% stated that this conduct was not necessary and 18% of them were unaware of the need to submit the study to such assessment. the written authorization given by the institution where the fc were carried out was not obtained in 56.6% of the studies. most of the authors (80.0%) stated that they had never read resolution 196/96. the proportion of fc submitted to a rec was significantly higher among authors that had read resolution 196/96 (p = 0.005). the fc design influenced the non-submission of the studies to a rec (p < 0.001). most of the fc that were authorized by the institution where they were carried out were submitted to a rec (p < 0.001). conclusion: most of the fc presented at the congress did not follow the brazilian regulations concerning the ethics in research.