Venetoclax (Venclexta™) is an oral selective inhibitor of the prosurvival protein BCL-2 and therefore restores the apoptotic ability of malignant cells. The drug arose from research by Abbott Laboratories (now AbbVie) during a collaboration with Genentech and is being co-developed by AbbVie and Genentech/Roche primarily for the treatment of haematological malignancies. Venetoclax is approved in the USA for use as monotherapy in patients with chronic lymphocytic leukaemia (CLL) with the 17p deletion (as detected by an approved FDA test) who have received at least one prior therapy, and is awaiting approval for similar indications in the EU and Canada. Venetoclax is also in phase I-III development as combination therapy for CLL, phase I/II development as monotherapy and/or combination therapy for non-Hodgkin lymphomas (including diffuse large B-cell lymphoma, mantle cell lymphoma, follicular lymphoma) and acute myeloid leukaemia, and phase I development for multiple myeloma, systemic lupus erythematosus and breast cancer. This article summarizes the milestones in the development of venetoclax leading to this first approval for CLL.