Spanish doctor Eufemiano Fuentes and four other defendants gave evidence in Madrid earlier this year, after a police operation which came to light in 2006 when anabolic steroids, transfusion equipment and blood bags were seized in raids.
The proceedings have attracted international attention because some of Fuentes's clients were successful professional riders, including American Tyler Hamilton who gave evidence in February.
Anti-doping authorities, who were represented in court, hope the trial will lead to evidence being made available of wrongdoing by athletes in sports other than cycling.
Fuentes, who denies doping, said in his opening testimony he also had clients in sports including soccer, tennis, athletics and boxing.
The judge is also expected to announce whether she will grant a World Anti-Doping Agency (WADA) request for access to the blood bags.
Spain is hopeful the trial will help to dispel the impression that the nation is soft on doping and boost Madrid's bid to win the right to host the 2020 Olympic Games.
The country is pushing through parliament anti-doping legislation which the government says will bring Spain into line with international norms.
(Reporting by Mark Elkington, editing by Ken Ferris)