RPC2018 was organized at Puerto Vallarta, Jalisco state, Mexico by Universidad Iberoamericana, Benemérita Universidad Autónoma de Puebla, Centro de Investigación y Estudios Avanzados del I.P.N. y la Universidad Nacional Autónoma de México. It continued the tradition of regular scientific meetings, first started in 1991 at Lecce, with following editions in Roma, Pavia, Napoli, Bari, Coimbra, Clermont-Ferrand, Seoul, Mumbai, Darmstadt, Frascati, Beijing and Ghent. This edition of the workshop focused on the design, performance and possible upgrade scenarios of large RPC systems, ageing and detector materials studies, electronics for RPCs, detector gas studies, and other applications like Therapy for medical physics and new ideas for RPC systems. The workshop had invited reviews and selected contributions, as well as a poster session.