Context: The benefits of taking a product line approach in order to achieve significant reductions in cost and time to market and, at the same time, increasing the quality has encouraged product line adoption. Objective: In this context, this study focuses on some SPL adoption aspects and has the following goals: investigate state-of-the-art SPL adoption, synthesize available evidence, and identify gaps between required strategies, organizational structures, maturity level and existing adoption barriers, available in the literature. Method: A systematic mapping study was undertaken to analyze the important aspects that should be considered when adopting SPL approaches. A set of four questions were defined in which 34 primary studies were evaluated. Results: A total of 34 primary studies were considered. They reported four different strategies (Incremental, Big Bang, Tactical and Pilot project), however there is insufficient information about how such strategies link to factors as organizational structure and process maturity. By investigating all primary studies we found 23 barriers to adoption. Conclusions: Researchers need to consider the relationships between SPL adoption and factors such as company maturity and organization structure in more detail. There is also a need for patterns to assist in SPL adoption and overcoming SPL adoption barriers.