Dengue continues to pose a threat to public health in our region. This threat has been recognized by countries throughout the region, which have taken action to protect their populations. National leaders also have acknowledged that they must act regionally in order to protect people within their own borders.The Association of Southeast Asian Nations (ASEAN) and the World Health Organization have formed an effective alliance to achieve a shared goal: a healthy and secure population. One clear sign of this cooperation was seen on 15 June 2011. ASEAN Health Ministers declared that day and each subsequent 15 June to be ASEAN Dengue Day. This important annual event allows ASEAN members, in coordination with WHO, to consolidate dengue prevention and control measures.ASEAN Member States ought to be congratulated for marking the successful launch of ASEAN Dengue Day and for affirming the regional partnership needed to address dengue. This book highlights some of the national and regional events that took place on 15 June 2011 to mark the launching of the first ASEAN Dengue Day.