She studied in Belgrade, 1961-1966. She retired in 2001. She has worked in the Building and Civil Development High School in Kikinda within the school centre for technical education (1966-1977), in the Urban Project Office within civil development organisation "Severni Banat" in Kikinda (1977-1987), she was the director of the Project Bureau within this organisation (1980-1982). She was the Secretary for Urban Development in Council of Kikinda in the period from 1987 until 1991. She worked on projects as  head urbanist in DP Urban Planning office in Kikinda until she retired (1991-2001).

Most of her working life, she worked on urban design and planning of Kikinda and towns and areas of northern Banat. Biserka Ilijasev is particularly interested in the architectural heritage of Kikinda. In the long-term studying of this area, the wisdom of the ancestors led to the successful development of settlements based on the valuable roots, which always carried the message of knowledge and skills. Her belief is that the urban matrix, known as «one road village» is the basis of further urban development and spatial planning of the towns in Northern Banat in Vojvodina . This contributed to recognition and preservation of identity of the townships in northern Banat at the end of 20th century. Besides the series of developed and completed city plans for municipalities Kikinda and Novi Knezevac and designed buildings in municipalities of Kikinda, Novi Knezevac, Nova Crnja and Čoka, she actively worked on the recognition of the profession within the Association of  Urban Developers of Serbia and Vojvodina.