The poster and flash talks sessions of the 1st Summit on Gender Equality in Computing (GEC 2019) offered the opportunity to undergraduate, graduate and PhD students, as well as young researchers and professionals of any gender, to share insights and knowledge with other participants, senior researchers and professionals in the field, to disseminate their research work and to receive comments about it, to practice their presentation skills and build confidence in presenting research work, and to benefit from discussing their ideas with the other GEC participants. The poster session included 35 posters out of 42 submissions. All poster submissions were peer reviewed by the Poster Evaluation Committee and all accepted poster presentations are made available on the Greek ACM-W website.