The objective of this chapter is to introduce the pathologies of basic computed tomography. This chapter is divided into six parts following as head, thorax, hepatobiliary system, pancreas, genitourinary tract, urinary bladder. Trauma is the most common indication for doing a plain computed tomography (CT) scan and it is the leading cause of brain hematoma or hemorrhage. Lungs are the most common site of tuberculous infection and its manifestations depend whether the infection is primary or postprimary. Acute pancreatitis refers to acute inflammation of the pancreas and is a potentially life-threatening condition. In this chapter, multiple choice question are provided along with their answers.