This work describes the importance of transthoracic ultrasonography (TUS) in the diagnosis of different chest diseases with its advantages being simple, safe, less expensive and bedside so it can potentially guide aspiration and biopsy of different pulmonary infiltrates, consolidation and lung access. TUS can also be used for the detection of pulmonary embolism. In contrast to computed tomography pulmonary angiography, TUS is non invasive and does not employ radiation and contrast material so can be applied during pregnancy and on patients with renal failure and those with allergy to contrast material. Finally, portable sonographic equipment also allows ultrasound evaluation at any time and in any place specially to patients in ICU and those who are mechanically ventilated.