In this study, the impact of molybdenum disulfide nanoparticles (MoS2 NPs) on the growth rate, pigment content, and primary metabolites of Spirulina platensis (S. platensis) microalga was investigated to enhance its commercial potential, being one of the most promising and nutritious cyanobacteria. Molybdenum disulfide nanoparticles possess remarkable characteristics across a wide range of applications. The results showed that exposure to 50 ppm MoS2 NPs increased the growth rate and beta-carotene content of S. platensis by 272 and 299%, respectively, compared to the control. Additionally, MoS2 NPs treatment increased lipid and carbohydrate content efficiently by 219 and 282%, respectively. On the other hand, the total protein content decreased by 18% under MoS2 NPs exposure compared to the control. The study concluded that MoS2 NPs, at an optimum concentration, could serve as a promising strategy to simultaneously increase biomass and beta-carotene synthesis in certain microalgae.