Dental care in Intensive Care Units -ICU, plays an important role in maintaining the health and well-being of critically ill patients. Although infection is a frequent manifestation in Intensive Care Unit (ICU) patients, the risk of infection by the oral cavity should also be considered. The immune response of this patient may be compromised, and consequently latent infections may intensify. The mouth is considered an ideal microbial incubator because of its characteristic of pH, presence of nutrients and hard surfaces. The relationship between periodontal disease and systemic conditions, including lung infections, is being explored. This study had the purpose of evaluating the odontology conditions in hospitalized patients with cancer in an intensive care unit at the Cancer Hospital of Londrina -Paraná, Brasil, quantifying the oral microbiota and evaluating bacterial resistance. Inclusion criteria involved critical patients of both sexes, two male and two female, ranging from 40 to 80 years old, submitted to mechanical endotracheal breathing. The presence of visible biofilm and xerostomia were the most prevalent. The results obtained are three patients who presented Klebsiella pneumoniae producer of Carbapenemase, due to the oral hygiene deficiency in patients hospitalized in the ICU, which are responsible for major systemic complications, increasing hospitalization time. Keywords