Cyber-Physical Systems (CPS) covers from M2M and Internet of Things (IoT) communications, heterogeneous data integration from multiple sources, security / privacy and its integration into the cloud computing and Big Data platforms. The integration of Big Data into CPS solutions presents several challenges and opportunities. Big Data for CPS is not suitable with conventional solutions based on offline or batch processing. The interconnection with the real-world, in industrial and critical environments, requires reaction in real-time. Therefore, real-time will be a vertical requirement from communication to Big Data analytics. Big Data for CPS requires on the one hand, real-time streams processing for real-time control, and on the other hand, batch processing for modeling and behaviors learning. This paper describes the existing solutions and the pending challenges, providing some guidelines to address the challenges.