Improper placement or positioning of an endotracheal tube may be lethal. Correct placement and positioning of endotracheal tubes is an essential component of life support during resuscitation from cardiac arrest or severe multiple trauma, during mechanical ventilatory support and during most surgical procedures under general anesthesia. To properly ventilate the lungs, endotracheal tubes must be inserted into the trachea rather than the esophagus, must be properly positioned in the mid-trachea and must remain properly positioned. We proposed to use optoacoustic technique for noninvasive monitoring of endotracheal tube placement and positioning. In this work we developed a compact, near infrared optoacoustic system for this application and performed in vitro tests of the system. The tests were performed in tissue phantoms (simulating overlying tissue) with an endotracheal tube. The optoacoustic measurements were noninvasively performed from the skin surface using custom-made optoacoustic probes. The placement and positioning of the endotracheal tubes were monitored with submillimeter axial and millimeter lateral resolution using the optoacoustic system. The obtained data indicate that optoacoustics can provide real-time, precise, cost-effective monitoring of placement and positioning of endotracheal tubes.