Transesophageal echocardiography (TEE) is an invaluable diagnostic tool, particularly in patients with inadequate transthoracic echocardiographic examinations. In addition, continuous TEE has been used to monitor ventricular and valvular performance in the intensive care unit and the operating room. However, current generation transesophageal probes have limitations in the critical care setting due to their size. Recently, a prototype miniaturized transesophageal probe was developed to overcome these limitations. This probe was used by five medical centers for 194 examinations. A large proportion of these patients were in the intensive care unit (43%), as well as mechanically ventilated (39%). Seventy percent (70%) of the subjects in this study were intubated nasally with the prototype probe, with a success rate of 88.5%. Oral intubation was successful in every case. Subject tolerance was good, and 25% of the patients were intubated for > 1 h. Nasal intubation with the probe was more likely in intensive care patients, ventilated subjects, and patients who were intubated for > 1 hour. TEE with this miniaturized probe is feasible and safe even in multi-instrumented critical care patients. This probe provides adequate diagnostic imaging capabilities and may allow imaging over prolonged periods of time, making it suitable for the serial monitoring of ventricular performance.