For the past 35 years, he has led a research team working on early detection and risk prediction of cancer, with a particular focus on screening for ovarian cancer. This has led to grant awards exceeding £50 million, more than 400 publications and an H-Index of over 80.

In 2005, Professor Jacobs established the Uganda Women’s Health Initiative, which conducted a series of projects in Uganda including a cervical cancer screening programme. He is a former President of the British Gynaecological Cancer Society and the European Society of Gynaecological Oncology; a Trustee of the Eve Appeal charity that he founded in 1985; and was a non-Executive Director of Abcodia Ltd, a medical diagnostics company he founded in as a spinout from his research from 2010-2022.

During his time at UNSW, Professor Jacobs held a number of additional roles including: Honorary Senior Principal Research Fellow of the Garvan Institute; Board member of Research Australia; Chair of the Australian Conservation Foundation's Leadership Forum for Energy Transition; Board member of the Business/Higher Education Round Table (BHERT); Board member of Ovarian Cancer Australia; Board member of The Conversation; Chair of the Sydney Partnership for Health Education, Research and Enterprise (SPHERE); Chair of the Group of Eight; and Board member of Universities Australia.