In the current study, the impact of silicon nanoparticles on germination characteristics and key growth parameters was investigated in Moso bamboo seedlings under cadmium (Cd) stress. The seeds were germinated at a concentration of 100 μM Cd alone and in combination with two levels of SiO₂ NPs (100 and 200 μM), and the results were compared with those from a control treatment. The results indicated that SiO₂ NPs significantly improved germination characteristics (GP, GR, and GI) under Cd toxicity but also led to increased mean germination time (MGT). On the other hand, the results indicated that the seedling growth indexes, seedling biomass and vigor indexes of Moso bamboo improved under a combination of 100 μM Cd and silicon nanoparticles. We concluded that SiO₂ NPs could ameliorate cadmium toxicity during seed germination and that the enhanced germination parameters improved seedling growth in Moso bamboo under Cd toxicity. We also found that SiO₂ NPs at 200 μM rather than 100 μM had a greater beneficial impact on the seed germination and the seedling growth under the Cd stress of 100 μM. Thus, the use of SiO₂ NPs may help in controlling Cd toxicity at the stages of seed germination and seedling growth in Moso bamboo (Phyllostachys edulis).