A trocar with a trocar sleeve, comprising a valve device arranged at the proximal end of the trocar sleeve and comprising a trocar pin which can be inserted axially into the trocar sleeve through the valve device and which has a hollow shaft and a tapering transparent distal tip. An endoscopic optical unit, such that the adjacent body tissue can be observed through the distal tip, can be introduced into the hollow shaft of the trocar pin, and a proximal insufflation connection allows a gas to be introduced into the trocar sleeve.
