The fisheries sector is an essential component of the Guinean economy. It accounts for an estimated 4.5 per cent of the GDP in 2020 and is dominated by small scale fisheries. The fishery sector is estimated to provide 238;000 jobs (direct and indirect) and support the livelihoods of just over one million people in Guinea; or 7.5 percent of the national population. This sector is also an important contributor to the food security of the population. In 2022; the Guinean Government adopted an ambitious halieutic and aquaculture strategy and associated investment plan for 2023-2027 based on the recent assessment of the sector; to address the main development challenges of the sector. A strategic orientation of the Strategy is the socio-economic development of aquaculture to improve the food security of the Guinean population. Indeed; aquaculture is the fisheries sector in Guinea that has the greatest development potential and can contribute in the medium term to increase the national fish supply and reduce the trade deficit in fisheries products. The World Bank has been working with Guinea for several years to support various sectoral reforms important for the country's transition to a sustainable blue economy. The World Bank has supported the fisheries sector through the West Africa Regional Fisheries Project (WARFP) which ended in December 2021 with very positive results in Guinea. A new project; Guinea - Climate Resilience; Food Security and Fisheries; which aims to strengthen food and nutritional security and increase the income of beneficiary communities; is currently under preparation. This study will inform the preparation of the Climate Resilience; Food Security and Fisheries - Guinea project by providing the World Bank with the necessary knowledge and technical elements to advise the Government on the opportunities and priority investments for the development of the aquaculture sector in Guinea. The proposed work constitutes a prerequisite for the socio-economic development of aquaculture to improve the food security of the Guinean population. The specific objective of the study is to address the current questions on the availability of agricultural products and by-products in sufficient quantity and quality to propose an intensification under technical and economic conditions of production favorable to the development of semi-intensive aquaculture.Indeed; fish farmers will not invest in a higher level of intensification than the existing one if they do not have access to quality inputs at a price that maintains the profitability of the activity.After having identified the different agricultural products and by-products currently used by fish farmers to feed fish in Guinea; and the factors influencing their use; the objective of the study is thus: (i) to carry out an inventory of the agricultural products and by-products available in Guinea that can be used as ingredients of a basic fish feed for semi-intensive aquaculture; (ii) to define the compositions and formulations of these feeds for semi-intensive farming; (iii) to carry out the Preliminary Draft Summaries of pilot fish farming feed manufacturing units; and to provide elements for the technical and economic analysis of these production units.