A style of diplomacy or code of conduct that has evolved in intra-ASEAN relations. It has been brought into regional institutions such as the ASEAN Regional Forum (ARF) and Asia-Pacific Economic Co-operation forum (APEC) by virtue of ASEAN's special role within them. Also presented in parallel formulations as the “Asian way”, “APEC way”, or “Asia-Pacific way”, the “ASEAN way” is often contrasted by Asian leaders and policymakers with what they perceive to be imported Western notions of diplomacy and multilateralism. In contrast to a Western, “American”, or even “Cartesian” style of diplomacy which some Asians regard as “formalistic” and focused on “legalistic” procedures and solutions, the “ASEAN way” stresses patience, evolution, informality, pragmatism, and consensus. Kusuma Snitwongse calls the “ASEAN way” “a distinct political process” developed by the association and characterized by “the habit of consultation and accommodation … fostered by frequent interaction”. The idea of a distinctively ASEAN or Asian way of diplomacy has not been universally accepted, however, and some strong critiques of the concept have been put forward.

Its origins pre-date the creation of the association in 1967. According to Estrella Solidum, the desire to avoid confrontation and acrimony in international relations and the importance of low-key, consensus-based diplomacy can be traced back to ASEAN's predecessor, the short-lived Association of Southeast Asia (ASA). In 1961, the founders of the ASA declared that problems in the region should be resolved using “Asian solutions that contain Asian values”. Solidum says the most important of these values was the use of “very low-key diplomacy [which] avoids fanfare before an agreement is reached”. She stresses the importance attached to “invisible ground rules” shared by ASEAN élites. Typically, scholars identify these shared norms as including a preference for informality and for non-legalistic and, thus, nonbinding approaches to diplomacy which allows for consensus, flexibility, and accommodation.

A central characteristic has been its cautious attitude towards formal institutionalization. Singapore's Foreign Minister S. Jayakumar called this ASEAN's predilection for “organizational minimalism”. Robert Scalapino has described it as a process of “soft regionalism” or “soft dialogue” while Alastair Iain Johnston uses the term “thin institutionalization”.