Fusarium oxysporum f. sp. lycopersici is a species reported to synthesize silver, gold, and cadmium nanoparticles when using biomass; it can produce and secrete many secondary metabolites hydrolytic enzymes involved in nanoparticle synthesis processes. However, the production of these components depends on the substrate where the fungus grows. The present work aims to evaluate the effect of the growth medium of Fusarium oxysporum in the synthesis of cadmium sulfide nanoparticles (CdS-NPs). The fungal biomass was obtained from a growth medium with nitrogenous components of higher and lower complexity (MGYP and DS respectively) and used for the synthesis of CdS-NPs using cadmium nitrate (Cd (NO3)2*4H2O) and elemental sulfur (S°). CdS-NPs exhibit two absorbance bands at 320 and 450 nm, with a fluorescence emission at 520 nm when excited with a wavelength at 365 nm. Transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction confirmed the presence of CdS-NPs with a mean diameter of 4.7 ± 0.7 and 4.9 ± 0.9 nm when MGYP and S media were used for biomass production, as well as atomic columns of CdS-NPs with A similar crystalline structure. However, it was also possible to appreciate fewer CdS-NPs when using the fungal biomass obtained from DS medium, which was confirmed by spectrophotometry through the absorption and emission bands at 450 and 520 nm.