The right of a defendant to be admitted to bail except when charged with a capital offence is predicated on the constitutional right to be presumed innocent until the prosecution proves guilt as well as on
the exercise of discretion of the court faced with application for bail; thus, there is an interplay of constitutional right and exercise of discretion by the court. This paper, adopting the doctrinal methodology appraised judicial authorities on the guiding principles for grant of bail, the constitutional right of a defendant to be presumed innocent and the exercise of discretion to grant or refuse bail applications. This work found among other facts that the constitutional right of a defendant in a criminal litigation to be presumed innocent until the contrary is proved is not at large, that there is no conflict between the presumption of innocence and exercise discretion. The administration of bail in the Nigerian criminal justice system has been discussed within the context of certain contemporary issues and challenges underlying the administration of bail. The issues discussed includes Right to Bail and the Presumption of Innocence, Seriousness of the offence and the Right to bail, Grant of bail in the absence of Proof of evidence, whether excessive bail conditions defeat the grant of bail, Bail pending appeal. The paper made recommendations for the regulation of exercise of discretion in granting or refusing application for bail, among which is the need to approach the issue of bail liberally.