Commentators and practitioners hold different views about ‘bifurcation’, i.e. the procedural technique of splitting the arbitral proceedings in distinct phases with a view of reaching decisions on discrete matters. The discussion mostly focuses on whether bifurcation is a source of efficiency or rather of useless additional costs and delays. This article argues that the debate is somewhat misled by a certain ambiguity, intrinsic to the three apparently intuitive notions of bifurcation, decision and efficiency, which has blurred the need for a flexible and balanced approach. It is submitted that the virtues and the pitfalls of bifurcation cannot be assessed in abstracto, but must be tailored to the peculiarities of each situation, in particular by considering: (i) the matter (a claim, an issue, an interim measure, a question of procedure) on which an early decision by the arbitral tribunal is sought, (ii) the form (a partial award, an interim award, an order) in which such decision is to be taken and (iii) the interests (of the parties, of the arbitral tribunal, of the States whose laws are at stake) that bifurcation may serve or jeopardise. Consideration of these factors shows that in different cases bifurcation may generate different effects (Inter alia, in terms of res judicata, risks of additional grounds for challenges to the award, interventions of State courts, impact on the timing of the arbitration). Therefore, arbitral tribunals faced with requests for bifurcation should first assess what such effects are and then balance them in light of the peculiar circumstances of the relevant proceedings. By so doing, their decision on bifurcation would acquire more legitimacy, while the conditions for recourse to this procedural tool would become more predictable to the parties.