Graduate of the Medical Academy in Warsaw, he continued his studies at the University of South Carolina USA. In the USA he worked for the Health and Human Services Finance Commission, which allowed him to learn about the functioning of the American health care system.
After returning to Poland, he worked as an academic assistant at the University Hospital of the Medical Academy in Warsaw at the Clinic of Vascular and Transplantation Surgery. After obtaining a second degree specialization in surgery, he started working in the 1st Clinic of Cardiac Surgery at the Institute of Cardiology in Warsaw, where he obtained a specialization in cardiac surgery. He received the degree of Doctor of Medical Sciences, his work was awarded by the Scientific Council of the Institute of Cardiology and won an award of the Polish Science Foundation. Author and co-author of numerous publications and speeches at medical congresses. For several years he was a secretary of the Polish Cardiac Surgeons Club.
He became interested in business activities first during his stay in the USA, where he established his first company in 1991. In 2005 he led to the establishment of the first medical company Allenort Kardiologia sp. z o.o., which started its operations in 2006 and contributed to the creation of a network of clinics of interventional cardiology and cardiac surgery (Allenort Cardiology).
Grzegorz Goryszewski was the originator and the main organizator of bringing to Poland the Gamma Knife technology. The project was implemented by the Allenort Radio-Neurosurgery Clinic. In 2012, Grzegorz Goryszewski received on behalf of the Gamma Knife Allenort Centre in Warsaw the second OSOZ (Polish National Healthcare System) award in the category: Innovative Ideas in Healthcare.
Grzegorz Goryszewski received the title: Health Market Manager 2012 (non-public institutions) – a distinction awarded by the combined editorial board of the prestigious monthly Rynek Zdrowia and the portal Rynek Zdrowia.pl.
In 2015, he established the Allenort Capital Fund, which aims to conduct investment activities focused on the medical industry and advanced IT technologies.
He is the Chairman of the Supervisory Board of the Polish Union of Specialist Hospitals, an organization established on his initiative and associated with the Confederation of Employers Lewiatan, he also was a Board Member of the Supervisory Board of ORIGIN TFI.
During the Psychiatry Congress Medforum 2018 he was awarded Golden Sinnapse – a prestigious award granted in the Medforum Psychiatry Congress poll, in the Psychiatric Innovation of the Year category – for creating and running a psychiatric project: "Allenort Therapy Clinics". Allenort was appreciated for the most interesting organizational solution in psychiatric care in Poland.