The paper analyzes the normative regulation of the procedural administrative decision institute, which was introduced into the Serbian administrative process as a novelty by the General Administrative Procedure Act (GAPA) in 2016. The paper aims to addresses three research questions: to determine the legislator's goal in regulating this insitute, to identify in which situations such a decision has to be made, and to establish how effective that type of decision is. At the beginning of the paper, the author focuses on the concept of effectiveness, including different, mutually opposed, approaches to defining that notion. The author points out the conceptual misunderstanding between efficiency and effectiveness, and their unjustified equalization. The main goal of introducing the institute of procedural administrative decision is the aspiration for greater protection of parties' procedural rights. The analysis of the text of the General Administrative Procedure Act has yielded seventeen basic types of procedural administrative decisions: a decision on rejecting the party's request, a decision not to allow alteration of the party's request, a decision on suspending the procedure, a decision on termination of the procedure, a decision on imposing a fine, decision on request, a decision on execution, a decision on securing the execution, a decision on appointing a temporary representative, a decision on denying representation to a quack lawyer for unlicenced practice of law, a decision on proposal for restitution, a decision on bearing preliminary procedure costs, a decision on exemption from procedure costs, a decision on payment of costs resulting from the absence or unjustified denial of testimony, a decision on compensation for damage to the holder, a decision on the proposal for providing evidence, and a decision on ordering an interim measure. The author concludes that the institute of procedural administrative decision can negatively affect the effectiveness of administrative proceedings due to the possibility of its unnecessary extension.