The study evaluated the effect of Bacillus thuringiensis (Bt) and Trichoderma asperellum (Ta) as biostimulants in hydroponically grown tendril pea (Pisum sativum) microgreens. A completely randomized experimental design was conducted under controlled conditions; the study included the root pea-spraying treatment with Bt, Ta, and their combination, alongside a non-inoculated control. The results showed that treatments with Ta significantly enhanced growth parameters, such as stem length and diameter, stipular leaf area, and fresh weight of the microgreens. Specifically, fresh biomass increased by 140% and dry biomass by 80% with Ta compared to the control, while combined treatment with Bt and Ta reduced nitrates by 39.6%. Bt and Bt + Ta increased chlorophyll b and carotenoids contents, suggesting improved photosynthetic activity. No significant differences in visual appearance were observed. In conclusion, the application of Ta and Bt can enhance tendril pea microgreens’ yield and certain biochemical (chlorophyll b and carotenoids) qualities without affecting their visual quality, supporting the application of these microorganisms as biostimulants. These findings underscore the potential to scale these treatments in commercial hydroponic systems, offering a sustainable approach to optimizing the production of this emerging crop type.