The right to be free from arbitrary detention is one of the most fundamental human rights recognized by various international human rights instruments. It is an important aspect of personal liberty of an individual and therefore, every democratic country has guaranteed the principle of the right to freedom from arbitrary detention its written constitutions. This study aims to examine the practice of arbitrary pretrial detention and its underlying causes in Awi nationality administrative zone. To achieve this objective, qualitative research approach was employed and both primary and secondary data sources were used. Primary data was obtained mainly through semi-structured in-depth interviews whereas secondary data from different literatures, legal instruments, reports and cases. There are several key pieces of legislation in Ethiopia that relates to arrest and detentions, most notably the FDRE constitution and CPCE. Like the constitutions of other democratic countries, the FDRE constitution has guaranteed the right to be free from arbitrary detention as a fundamental human right. Nevertheless, the violation of this right by the law enforcement agencies, is a common phenomenon in Awi nationality administrative zone. The study revealed that Police have arrested and detained individuals without sufficient legal grounds and contrary to procedures established by the FDRE Constitution and CPCE , these include: failure to inform rights and reasons of detention; failure to present detainees within 48 hours before a judge; lengthy pretrial detention; lack of legal representation in pretrial phase; existence of significant barriers to challenging the lawfulness of their detention in courts and absence of compensation when their rights have been abused. Judges and prosecutors have also failed to effectively play their role in limiting the length of pretrial detention and preventing or ending arbitrary detentions. The study also identified underlying causes that play a role in Arbitrary pretrial detention in the study area, including: inadequate legal framework; corruption; poor coordination among criminal justice sectors; inefficient oversight and accountability mechanisms; lack of legal representation and legal awareness; and inadequate resource and training of police. Finally, the study provided possible recommendations to reduce arbitrary pretrial detentions.