Tomato production is threatened by climate change. High temperatures lead to a decrease of fruit production which correlates with a decrease of pollen fertility. The low fertility of tomato pollen under heat stress has already been linked with the alteration of specific compounds, but most of the previous studies were done by studying only a few compounds present in pollen. In this thesis, we used a technique called “untargeted metabolomics” that allowed us to easily identify a high number of pollen compounds. We explored the content of pollen and its surrounding tissue coming from different tomato varieties under control and high temperature conditions. We showed that an early step of the pollen development is likely to be responsible for the low fertility of mature pollen under heat stress. Several compounds were putatively associated with tolerance to high temperature such as specific flavonoids, polyamines and alkaloids. These compounds can be further used as markers in breeding programs to develop new tomato varieties tolerant to high temperatures.