Welcome to the second workshop on Semantic Data Analytics and Bioinformatics (SDAB 2015) to be held in November 2015, in conjunction with IEEE BIBM 2015 conference in Washington, D.C. The workshop aims (1) to bring together researchers from disciplines related to semantic data analytics and computational biology to share their research findings and their insights; (2) to serve as a forum for participants to discuss the challenges and the opportunities in the fields of semantic data analytics and bioinformatics; and (3) to provide a networking opportunity for collaborations in regional, national, and international research programmes.