Raul Fain, 66, of Toronto, told an EU-run panel of three judges that he sought foreign organ donors after doctors told him he could wait up to 12 years for such an operation in Canada.
Fain testified from Canada via a video link to the trial of seven Kosovars suspected of involvement in the criminal network. Kosovo law forbids the removal and transplant of organs.
Fain was shown photos of a building that he identified as the Medicus clinic in Pristina where he was driven for his kidney transplant in June 2008.
The witness said he had been met in Istanbul, Turkey, by Israeli national Moshe Harel, who allegedly organized the transplant, and flown to Kosovo together with an elderly German man also seeking a kidney and two Russian women prepared to each donate one.
Harel and Turkish Dr. Yusuf Sonmez, who allegedly performed the operations, remain at large and are being sought by European Union prosecutors in charge of the case.
Prosecutor Jonathan Ratel has said the Russian women were just two of some 20 foreign nationals "recruited with false promises of payments" in 2008.
Victims were promised up to $20,000 (€4,500), while kidney recipients were required to pay between $105,000-$132,000 (€80,000 and €100,000), according to Ratel.
Fain testified Friday that his operation took place in a cold, dark room at the Medicus clinic and that he spent five days recovering before flying back to Canada.
He said he saw the two Russian women at the clinic but did not talk with them. Asked by the prosecution if he had received on of their kidneys, Fain said: "I believe so."
The case began with indictments in November 2010, and the trial began last year. It is providing a stark look at a crime network that allegedly organized organ transplants and included criminals from countries such as Kosovo, Moldova, Ukraine, Turkey, Russia and Israel.
Ratel said Friday he will ask Council of Europe investigator Dick Marty to testify at the trial. Marty alleged in a report last year that Kosovo Prime Minister Hashim Thaci and other citizens who once served as rebel commanders in the Kosovo Liberation Army had run detention centers on Albania's border with Kosovo where civilian captives, including Serbs, were killed and their organs sold on the black market during Kosovo's war for independence from Serbia.
Thaci and Albania's government have denied those allegations.
Ratel is part of a 3,000-strong EU rule of law and police mission in Kosovo that deals with sensitive cases such as war crimes and organized crime.