Abstract Background Critical results consist of laboratory test results that require immediate intervention or decision-making by the responsible medical team, as they pose a risk to the patient's life. To manage the process of communicating critical results, it is also necessary to define the indicators, goals and systematic comparability through benchmarking. Methods The performance of the indicators measuring the critical results process for the year 2023 was analyzed. Performance indicators such as resolution time, success and failure rate in communication, delay rate in communication and the rate of open incidents related to the communication of critical results were monitored using a Business Intelligence tool. Results In the first two months of 2023 the results reflected the absence of parameters in the LIS for effective communication of critical results. September and October there was a high turnover rate in the laboratory in addition to the change in the hospital care profile in which the laboratory medicine service was inserted. These causes culminated in a number of 122 (1.48%) communication failures, representing an increase of 1,120% compared to the first two months of the year. On the other hand, there was a significant improvement in the average communication time for critical results, decreasing from approximately 736 hours to 184 hours(reduction of around 75%). There was also a reduction in communication delay of approximately 67%. These numbers corroborate the parameterization actions in the system aimed at speeding up the process. As a continuation of the improvement actions, the laboratory implemented goal setting for the resolution time indicator and also the periodic meeting for critical analysis of the results.In addition to these actions, the laboratory approached the hospital's clinical staff, making it possible to provide clarity on the difference between compulsory notification and critical results. This clarification allowed for the establishment of a list of exams considered critical, in order to meet the hospital profile, as well as to define the communication flow. For the success indicator in communicating critical results, there was a 22% improvement when comparing the last two months of 2023 with the first two months of the same year. In the last two months of the year, this indicator performed at 99.4%, corroborating the study published by Noronha et al., (2016), where the effectiveness rate in critical results communication was 96.1%. Comparing with the study by Noronha et al., (2016), where the biochemistry sector had the highest rate of critical results communication failures (73.8%), followed by the Emergency Room (78.6% ) and ICU (16.7%), the findings of this study highlighted the top 3 detracting sectors: Biochemistry (68%), “UPA” - Emergency Care Unit (42.1%) and ICU (21.4%), making data superimposable. Conclusions The communication of critical results has challenges related to its effectiveness, especially in hospital contexts. As a critical and high-impact activity, constant actions are necessary to continuously improve the process. Actions should take into account: interactions with attending physicians, the development and training of the internal team, and constant checks of the LIS, as technology can support the process management.