This essay applies a simple economic model of the plea bargaining process to the two-tiered structure of negotiated pleas and sentences in South Africa. Bargaining in South Africa proceeds along one of two tracks. A formal procedure, authorized and regulated by s 105A of the Criminal Procedure Act, gives defendants represented by counsel access to precise information about the terms of the bargain before the plea is made and permits them to withdraw their pleas should the sentencing judge reject the agreement. In contrast, an older, informal procedure, governed by s 112, applies to defendants without counsel and grants them significantly less information and agency in the bargaining process than does the s 105A procedure. The model illuminates the central role of information and uncertainty in the defendant's decision to plead guilty or insist on a full trial, and suggests that if all plea bargains were governed by the formal procedures of s 105A, the system would more effectively represent the interests of both prosecutors and defendants by producing more bargains, and fewer trials, in cases where both sides want to avoid trials and consummate plea bargains. A final section considers the constitutionality of plea bargaining under ss 35 and 36 of the Constitution of the Republic of South Africa. It reviews the constitutional history of plea bargaining in the United States to emphasise the differing perspectives on the constitutionality of plea bargaining demanded by significant variations in substance and interpretative style in the two constitutions. The essay concludes by briefly suggesting the arguments that might be made against the constitutionality of plea bargaining under s 35 and the corresponding limitations analysis that might be raised to justify the practice should it be found to violate s 35.