She was born in Ankara, in 1933. The picture she drew while attending last class of secondary school; which was sent by her art teacher to an exhibition organized nationwide in Turkey; by Faculty of Languages, History and Geography - was shortlisted among the top 20 students. She graduated from Istanbul Fine Arts Academy, High Art Department, in 1954; with outstanding success. She opened her exhibition in 1957, in Ankara. During this time, she studied classical archaeology under the leadership of Ekrem Akurgal in the Faculty of Languages, History and Geography, for one year. In 1959, she went to Florence with the scholarship she gained from the government of Italy. At the end of the scholarship period, she settled in Rome and established her own studio. She was invited to many important exhibitions and competitions and she was given many rewards. In 1966, after her returning Turkey; she made great wall pictures comprised of ceramic and mosaic for ODTU Engineering Faculty, Kizilay Branch of Ziraat Bankasi and Seker Bank. She produced art works by using amulet beads with the techniques she formed; for Divan and Etap Marmara Hotels and General Directorate of Turkiye Is Bankasi in Ankara. Unfortunately, except for the work in ODTU, none of the rest is not known, where they are now. Gencay Kasapci is the first artist to use beads in her works.
In 1954, by finding the furnaces which make beads only in one type and colour; she convinced them to use more colours and forms and they helped her to be more artistic with the new dimension of products. In 1958, the table she made from the beads which was bought by the Ministry of Tourism was exhibited in a Brussles Fair, Turkey Pavilion. Between 1976-1983, she executed the roles of the Management and Art Consultancy in Ankara Vakko Art Gallery and she enabled many young artists be known in the art circles. In 1994-1995, she erected the monuments of “Freedom” and “Orange Tree”. Her pictures were printed as postcards by institutions such as UNICEF, TEMA, TAP. Gencay Kasapci who has many rewards from various institutions and many high ranks in many competitions – continues her life and works in Mersin.