In this presentation, we will summarise the results of a recent systematic review of the published literature on the key parameters of the treatment cascade among female sex workers. Using different examples from transmission dynamics modelling studies of HIV transmission and ART use, we will discuss the potential impact of scaling-up ART for FSWs in contrasting epidemiological settings. We will present results of the impact of ART programmes in settings with different HIV prevalence levels in the general population (very low, low/medium, high) and different history of condom use interventions and level of ART scale-up already achieved. For example, we will compare the impact of different ART scale-up scenarios and eligibility criteria in districts of India (low prevalence settings) where there has been and there has not been a large-scale condom use intervention implemented in recent years. Other settings with higher HIV prevalence such as Benin, Burkina Faso, Columbia or Kisumu will be considered. We will also contrast the impact of ART programme targeted to FSW on HIV transmission in the general population and assess the influence of key parameters of the treatment cascade on the impact of ART among FSWs.