Thoracic ultrasonography can be used for diagnostic purposes as well as a guide for diagnostic and therapeutic interventions.When the lesion or fluid collection has been located and the patient properly positioned, the angle of the needle is identified with respect to the transducer. The insertion tract should transgress the smallest possible area of aerated parenchyma. The needle can be introduced with a free-hand technique or with the aid of a needle guide. Correct planning of the procedure reduces intervention time and decreases the risk of complications.The main indications are superficial masses that require biopsy, pleural and parenchymal lesions formerly biopsied with CT or fluoroscopic guidance, and fluid collections that need to be drained.Ultrasound, thanks to its widespread use, simple execution, and low costs, represents a safe, manageable guide for thoracic interventions.