This volume contains the papers presented at the Second International Workshop on Semantic Technologies (IWOST) held on November 02-03, 2015 at the King Mongut's Institute of Technology Ladkrabang, Thailand. The workshop is an activity of the cluster Semantic Technologies within the project Swap and Transfer. This project is funded by the EU within the Erasmus Mundus programme and aims at fostering sustainable development, innovation and technology transfer.

There were 8 submissions. Each submission was reviewed by at least 2 program committee members. The committee decided to accept 7 papers. The program also includes invited talks by Boontawee Suntisrivaraporn from the Thammasat University in Thailand on Reasoning, Modeling, Using: Web Ontology Language for the Semantic Web and Phan Minh Dung from the Asian Insitute of Technology in Thailand on Argumentation for Practical Reasoning (joint work with Thang Phan Minh).

The editors would like to thank Peter Steinke and Christoph Wernhard for their help in setting up the web page and compiling this proceedings, respectively, as well as Isara Anantavrasilp for organizing the event at King Mongut's Institute of Technology. We thank the Swap and Transfer project as well as the King Mongut's Institute of Technology for supporting the workshop financially. Finally, we are indepted to Easy Chair which made the organization of the workshop easy for the chairs.