The economy based on non-timber forest products (NTFPs) often relies on informal actors and activities, based on specific logics and worldviews. While the effects of these new markets on traditional societies and lifestyles have been studied, gender is rarely addressed. However, authors have shown that the inclusion of traditional products in markets, including NTFPs, tends to dispossess women of resources and of their activities, making the poorest fringe of the world's population even more vulnerable. We hypothesise that by understanding the changing roles of women and men in the markets for one NTFP, açaí, we can explain how, and under what conditions, women manage to be part in the supply chain and thus become economic stakeholders in their own right. The method is based on monographic studies conducted between 2014 and 2019 in the states of Pará and Amapá (Brasil), and in French Guiana, in different marketing contexts: home sales, short circuits, export. Practices surrounding the harvesting, processing and consumption were described and supplemented by historical interviews on traditional practices and know-how, as a reference time preceding the marketing of açaí. Our results show that fruit-gathering was not a gendered activity, but was carried out by young people regardless of their sex, or on specific occasions when people were going out into the forest (hunting for instance). The urbanisation of lifestyles, combined with the loss of links with the forest, seems to have accelerated the process of masculinisation of fruit-gathering. Processing used to be carried out by women - although not exclusively; it is now the preserve of men in Brazil, including in micro-processing units. In French Guiana, while the açai economy is still invisible, processing is dominated by women, including for large volumes. Permanent control of processing, for commercial purposes, is systematically accompanied by financial independence (enabling the purchase of equipments). Our stud