The 6th edition of the Portuguese Software Engineering Doctoral Symposium (SEDES'2016), was held in September 16, 2016, in Lisboa, Portugal, co-located with the QUATIC'2016 conference. The aim of this symposium is to bring together Software Engineering PhD students supervised or co-supervised by faculty members of Portuguese Universities in a constructive environment, where they can present and discuss their ongoing PhD projects, receive feedback and valuable suggestions from faculty and peers, as well as network with other researchers in the field. It follows the tradition of previous editions, held in Coimbra, Caparica, Porto, Lisboa, and Guimarães.