The third to eighth intercostal arteries (ICAs) were bilaterally dissected in 10 cadavers to assess their length and possible routes to coronary arteries if used as in situ grafts. The mean lengths for the intercostal arteries harvested were 27.0 +/- 2.9 cm on the left and 27.4 +/- 3.2 cm on the right. The shortest anatomic route to the coronary arteries of the in situ ICAs harvested was medial to the lung and either superior to or inferior to the hilum. By using either the superior or inferior routes in situ ICAs were long enough to reach the major coronary artery territories in all cadavers. The most suitable ICAs for grafting the coronary arteries and the shortest routes were as follows: left anterior descending--left fifth ICA by inferior route; circumflex coronary artery-left fifth ICA by inferior route; and right coronary artery-right seventh ICA by inferior route. We conclude that it is anatomically feasible to use the intercostal artery as an in situ graft in coronary artery operation.