Tomato (from the genus Solanum lycopersicum) is a widely cultivated and important crop worldwide. The production of tomatoes suffers huge losses in production due to diseases such as early blight, fusarium wilt, damping off, late blight etc... Early blight, whose causal agent is Alternaria tomatophila, results in major loss both in quantity and quality of fruit yield, crop loss is variable but can reach up to 78%. The disease symptoms appear as dark lesions on stems, leaves and fruits of tomato which can be necrotic. We evaluate the efficacy of 26 strains of yeasts in controlling tomato early blight in 2 different settings: on tomatoes in the greenhouse and in dual culture assays in the laboratory. The purpose of this is screening potential biological control agents amongst these yeasts for tomato early blight. We also test early blight causal pathogen’s spore production according to the storage method, in different growth chambers to identify the ideal storage/growth conditions for future experiments. We also perform microscopic observation of the yeast cells, and a single spore isolation of A. tomatophila. All the tested yeasts showed positive rates of inhibition of A. tomatophila to varying degrees. In vivo a few yeasts showed promising disease controlling potential. The ideal storage condition is -80°C in 25°C or 28°C with a 12h photoperiod. They all exhibit different bioactivity mechanisms warranting further study