The Understanding on Rules and Procedures Governing the Settlement of Disputes (DSU) prescribes three different types of arbitration which are ancillary to the Panel and Appellate Body functions of the WTO dispute settlement system (DSS). These are the arbitrations for determining the implementation timeline under Article 21.3 (c) of the DSU and two other types of arbitration under Articles 21.5 and 22.6. This article focuses on some specific approaches and functions of Article 21.3 (c) arbitrations and examines the procedural actions which are related to determining a suitable implementation time for developing countries. It investigates the consistency and coherence of practice in selected arbitral awards in which developing countries claimed “particular attention” either as complainant or as implementing parties. This article points out that the lack of specific guidelines in the DSU is the substantial cause for arbitrators’ noncompliance with Article 21.2 provisions in Article 21.3 (c) arbitrations, which questions the procedural fairness of such arbitrations. This situation, amongst others, reiterates the urgent necessity to amend the relevant DSU rules.