This “geographic and thematic” issue of the American Journal of Ethnomedicine focuses on the traditional medicines in trade in Asia on the 30th anniversary of the 1988 Chiang-Mai Declaration, an output of an historic meeting organized by WHO, IUCN and WWF. The emphasis on the Asian countries that represent the highest volume and value of medicinal plants trade in the world is deliberate. Not only because of the scale and speed of changes in traditional medicines trade in Asia, but also to highlight the conservation and sustainable use issues being faced today. In 1988, few studies had been done on the informal sector trade or on medicinal plant value-chains and even fewer studies on cross-border trade in medicinal plants or fungi. At that time, e-commerce in Traditional and Complementary Medicine (T&CM), so common today, did not even exist. And no comparitive, repeat studies of traditional medicines markets had been done at all. Thirty years later, this special issue illustrates how the traditional medicines trade has grown and changed. Links between medicinal plant conservation, scarcity and price on one hand and quality, safety and adulteration on the other are better understood. E-commerce in T&CM has grown exponentially, due to 51% of the world's population having internet access by 2017. Yet despite global policy goals for conservation and sustainable use, the challenges facing medicinal plants conservation are greater than ever before. Consequently, the need for cooperation between the health-care and conservation sectors recognised in 1988 is even greater today. And this is recognised in WHO's 2014–2023 strategy for traditional medicines, which identifies the need to raise awareness about issues of biodiversity and conservation as an important strategic action (WHO, 2013). This Special Issue is a small contribution towards that goal.