The use of performance-enhancing tactics or more formally known as PEDs, and more broadly, the use of any external device to nefariously influence the outcome of a sporting event has been a part of the Olympics since its inception in Ancient Greece. One speculation as to why men were required to compete naked was to prevent the use of extra accoutrements and to keep women from competing in events specifically designed for men.
 Athletes were also known to drink "magic" potions and eat exotic meats in the hopes of giving them an athletic edge on their competition.
 If they were caught cheating, their likenesses were often engraved into stone and placed in a pathway that led to the Olympic stadium.
 In the modern Olympic era, chemically enhancing one's performance has evolved into a sophisticated science, but in the early years of the Modern Olympic movement the use of performance-enhancing drugs was almost as crude as its ancient predecessors. For example, the winner of the
marathon at the
Thomas Hicks, was given
brandy by his coach, even during the race.
During the early 20th century, many Olympic athletes discovered ways to improve their athletic abilities by boosting testosterone. As their methods became more extreme, it became increasingly evident that the use of
performance-enhancing drugs was not only a threat to the integrity of sport but could also have potentially fatal side effects on the athlete. The only Olympic death linked to athletic drug use occurred at the
Rome Games of 1960. During the cycling road race,
Knud Enemark Jensen fell from his bicycle and later died. A coroner's inquiry found that he was under the influence of
amphetamine, which had caused him to lose consciousness during the race.
 Jensen's death exposed to the world how endemic drug use was among elite athletes.
 By the mid–1960s, sports federations were starting to ban the use of performance-enhancing drugs, and the IOC followed suit in 1967.
The first Olympic athlete to test positive for the use of performance-enhancing drugs was
Hans-Gunnar Liljenwall, a Swedish
pentathlete at the
1968 Summer Olympics, who lost his bronze medal for alcohol use, 'two beers to steady his nerves'.
 Liljenwall was the only athlete to test positive for a banned substance at the 1968 Olympics, as the technology and testing techniques improved, the number of athletes discovered to be chemically enhancing their performance increased as well.
The most systematic case of drug use for athletic achievement is that of the East German Olympic teams of the 1970s and 1980s. In 1990, documents were discovered that showed many
East German female athletes, especially swimmers, had been administered
anabolic steroids and other drugs by their coaches and trainers. Girls as young as eleven were started on the drug regimen without consent from their parents. American female swimmers, including
Shirley Babashoff, accused the
East Germans of using performance-enhancing drugs as early as the
1976 Summer Games.
 Babashoff's comments were dismissed by the international and domestic media as sour grapes since Babashoff, a clear favorite to win multiple gold medals, won three silver medals - losing all three times to either of the two East Germans
Kornelia Ender or
Petra Thümer, and one gold medal in a relay. There was no suspicion of cheating on the part of the East German female swimmers even though their medal tally increased from four silvers and one bronze in
1972 to ten golds (out of a possible 12), six silvers, and one bronze in
1976. No clear evidence was discovered until after the fall of the
Berlin Wall, when the aforementioned documents proved that East Germany had embarked on a state-sponsored drug regimen to dramatically improve their competitiveness at the Olympic Games and other international sporting events. Many of the East German authorities responsible for this program have been subsequently tried and found guilty of various crimes in the German penal system.
According to British journalist
Andrew Jennings, a
KGB colonel stated that the agency's officers had posed as anti-doping authorities from the
International Olympic Committee to undermine
doping tests and that Soviet athletes were "rescued with [these] tremendous efforts".
 On the topic of the
1980 Summer Olympics, a 1989 Australian study said "There is hardly a medal winner at the Moscow Games, certainly not a gold medal winner, who is not on one sort of drug or another: usually several kinds. The Moscow Games might as well have been called the Chemists' Games."
Documents obtained in 2016 revealed the Soviet Union's plans for a statewide doping system in track and field in preparation for the
1984 Summer Olympics in Los Angeles. Dated prior to the country's decision to boycott the Games, the document detailed the existing steroids operations of the program, along with suggestions for further enhancements.
 The communication, directed to the Soviet Union's head of track and field, was prepared by Dr. Sergei Portugalov of the Institute for Physical Culture. Portugalov was also one of the main figures involved in the implementation of the Russian doping program prior to the 2016 Summer Olympics.
A very publicized steroid-related disqualification at an Olympic Games was the case of
Ben Johnson, who won the
Men's 100 metres at the
1988 Seoul Olympics, but tested positive for
stanozolol. His gold medal was subsequently stripped and awarded to runner-up
Carl Lewis, who himself had tested positive for banned substances prior to the Olympics, but had not been banned due to a lack of consistency in the application of the rules. At that time National Olympic Committees had leeway to determine whether a specific athlete met the criteria to be banned from Olympic competition.