The 2007 Tour de France was affected by a series of scandals and speculations related to doping. By the end of the Tour, two cyclists were dismissed for failing tests and the wearer of the yellow jersey was voluntarily retired by his team for lying about his whereabouts and missing doping tests. A fourth rider was confirmed to having used doping while in a training session prior to the 2007 Tour and a fifth rider failed tests late in the race, with his result being officially announced just after the end of the Tour. During the competition, two teams were asked to withdraw after at least one member was found to have doped.

Blood doping is a form of doping in which the number of red blood cells in the bloodstream is boosted in order to enhance athletic performance. Because such blood cells carry oxygen from the lungs to the muscles, a higher concentration in the blood can improve an athlete's aerobic capacity (VO2 max) and endurance. Blood doping can be achieved by making the body produce more red blood cells itself using drugs, giving blood transfusions either from another person or back to the same individual, or by using blood substitutes.