The discovery of new antimalarial drugs able to target both the asexual and gametocyte stages of Plasmodium falciparum is critical to the success of the malaria eradication campaign. We have developed and validated a robust, rapid, and cost-effective highthroughput reporter gene assay to identify compounds active against late-stage (stage IV and V) gametocytes. The assay, which is suitable for testing compound activity at incubation times up to 72 h, demonstrates excellent quality and reproducibility, with average Z= values of 0.85 ؎ 0.01. We used the assay to screen more than 10,000 compounds from three chemically diverse libraries. The screening outcomes highlighted the opportunity to use collections of compounds with known activity against the asexual stages of the parasites as a starting point for gametocytocidal activity detection in order to maximize the chances of identifying gametocytocidal compounds. This assay extends the capabilities of our previously reported luciferase assay, which tested compounds against early-stage gametocytes, and opens possibilities to profile the activities of gametocytocidal compounds over the entire course of gametocytogenesis.T he complex life cycle of the Plasmodium falciparum parasite, responsible for malaria, involves a human host, in which the intraerythrocytic asexual stages of the parasite cause the disease manifestations, and an anopheline mosquito vector, in which the parasite transmission stages genetically recombine and develop to successfully infect new human hosts. Parasite transmission to both the mosquito vector and the next human host rely on the sexual stage gametocytes. In P. falciparum, gametocytes emerge in low numbers from the asexual population and mature over a 10-to 12-day period, progressing through five morphologically distinct stages (I to V) (1). Mature stage V gametocytes can remain infective to the mosquito for an extended time, even if the asexual parasite population has been decreased by therapeutic drugs (2).The last 15 years have witnessed an unprecedented effort in the fight against malaria, with the deployment of large-scale interventions, including the distribution of artemisinin-based combination therapies (ACTs); targeted chemoprophylaxis of patient populations at particular risk, notably pregnant women and children under the age of 5 years; and vector control measures, including insecticide-treated bed nets. As a result, a 48% decrease in global malaria mortality rates was achieved between 2000 and 2015, and 16 countries have successfully eliminated malaria since 2010 (3). Although these impressive achievements have required a substantial economic outlay, it has become increasingly clear that an aggressive strategy aimed at malaria eradication is the only sustainable, albeit ambitious, goal in the long term (4). Achieving this ultimate goal is challenging, as malaria claims nearly 440,000 lives annually, and nearly half of the world's population is at risk of contracting the disease (3). The emergence of parasites resistant to current ...