Olaparib (Lynparza™) is an oral, small molecule, poly (ADP-ribose) polymerase inhibitor being developed by AstraZeneca for the treatment of solid tumours. The primary indication that olaparib is being developed for is BRCA mutation-positive ovarian cancer. A capsule formulation of the drug has received approval for use in this setting in the EU and USA, and a tablet formulation is in global phase III trials (including in the USA, EU, Australia, Brazil, Canada, China, Israel, Japan, Russia and South Korea). In addition, phase III trials in breast, gastric and pancreatic cancer are underway/planned, and phase I/II investigation is being conducted in other malignancies, including prostate cancer, non-small cell lung cancer, Ewing's sarcoma and advanced cancer. This article summarizes the milestones in the development of olaparib leading to this first approval for ovarian cancer.