Post-harvest losses refer to food losses that occur between harvest and consumption, i.e. before the product reaches consumers. The objective of this study was to establish a diagnostic and evaluative situation of the three sectors tomato, potato and cabbage, in terms of post-harvest losses (PHL) at the various levels of the value chain in high production areas in Niger. On one hand, 12 groups of around 60 members each were interviewed in focus groups separately, and 120 producers (10 producers per group and by product) were investigated on the other hand. The study identified the different types of PHL, the extent of these losses, the main factors behind these losses, their impact on the producer’s income and their consequences on the food and nutritional security of households. It also made it possible to identify the strategies adopted by producers to cope with these significant losses. The results of this study showed that most of the PHL are caused by physical, microbiological and physiological factors, except for potatoes where the bad faith of wholesalers devaluating an important quantity of the product, remains the main constraint causing enormous qualitative losses to producers (about 35 %). The study filled a gap in the field of post-harvest food losses, particularly in the case of market gardening. The professionalization of actors in pre-harvest techniques and their support with small processing and/or preservation equipment’s remain an alternative.