Combinatorial methods are a promising modern approach to software testing. In particular, pairwise testing, which requires testing all pairs of possible values for any pair of input parameters, has shown a high level of fault detection. A more general approach, t-wise testing, which is an extension of pairwise testing for t from 3 to 6, considers a combination of any t input parameter values to be covered by at least one test. It requires more test cases but provides even better results. Combinatorial testing (CT) is also an effective approach to testing hardware and software configurations. The CTA 2017 workshop aims to bring together researchers and practitioners working on CT. The workshop will provide a platform for the discussion of problems in the theory and practice of CT with a focus on its applications in different domains. Participants will be able to use this opportunity to share their knowledge through informal discussions, develop new ideas, and establish new collaborations on CT topics.