The Chadian judicial system and the criminal code were based on the French criminal justice system. The traditional system of law presided over by local chiefs and sultans, however, has been preserved for property and family affairs and for cases of local petty crime. These customary courts, as they were called, have been described as generally effective and fair in rendering sentences. In theory, decisions of the customary courts were subject to appeal to the regular courts.

Normal protections against arbitrary arrest, as well as restraints on the actions of police and judicial authorities, were embodied in the criminal code statutes. Detention without being charged was permitted only for persons under suspicion of having committed a crime. In theory, the rights of detainees included access to counsel and prompt notification of the charges under which they were being held. The death penalty could only be imposed after a competent court had established guilt and rendered a verdict. In actual practice, the judicial system was severely undermined by the breakdown of local government throughout much of the country. According to human rights reports of the United States Department of State, most Chadians did not get speedy trials, and many were held for extended periods before being released without trial. There were only a few trained lawyers, judges, and other court personnel in the country, and law books were not widely available. Although in the late 1980s the Habré government was trying to rebuild the judicial system, the lack of individuals with the necessary legal training hampered the appointment of judges and examining magistrates.

All judges and judicial officers were appointed by the president. The courts were subject to the influence of the executive branch, especially in political and internal security cases, and individuals regarded as endangering the security of the state were subject to indefinite detention without trial. In 1987 the independent human rights group, Amnesty International, reported the detention of several former Chadian exiles upon their return to Chad, as well as the detention of relatives of government opponents. Although there were no reports of disappearances, nor confirmed reports of torture in 1987, Amnesty International expressed concern over the government's failure to account for a number of people who had disappeared after being detained in earlier years.

The Department of State and other groups have described Chadian prison conditions as primitive. To some extent, the conditions were a reflection of the general poverty of the country rather than a deliberate policy. The scanty prison rations made it necessary for prisoners to have a source of food outside the prison food was usually supplied by the prisoners' families. Most prison personnel had no professional training, and many prisoners complained of beatings and other forms of abusive treatment. Conditions in government detention centers for political prisoners, where outside visitors were not permitted, were worse than those in the regular prisons. Those prisoners of war to wh2b4 whom the International Committee of the Red Cross had access (mostly Chadians captured before early 1986) were reported to be receiving adequate treatment. As of late 1987, the Chadian government was continuing to deny the Red Cross access to an estimated 2,000 Libyan prisoners of war captured since 1986 because the Libyans had refused the Red Cross access to FANT prisoners held in Libya.

Data as of December 1988