In the following review, the development of the thorax and abdomen, as described by embryologists and anatomists in modern embryological text books, is compared with sonoanatomic descriptions from 2D and 3D ultrasound studies, week by week in the first trimester. The anatomic descriptions are limited to details that are of interest for the understanding of ultrasound examinations. For the second and third trimester, the description of the sonographic development of the thorax and abdomen is divided into thoracic skeleton, diaphragm, lungs, oesophagus, stomach, liver, spleen, bowel and gall bladder. The review is restricted to the normal development, appearance and biometric assessment of these organs; and discusses topical literature.