The early stages of seagrass life are marked by the development of seagrass seedlings. Enhalus acoroides is a persistent seagrass species with a high prevalence in tropical waters. The decline in water quality caused by human activities, such as microplastic contamination, is suspected to affect the growth and development of seagrass seedlings. This study examines the impact of microplastic exposure on the growth, chlorophyll content, and anatomical structure of Enhalus acoroides seedlings. This experimental research included four treatments: Treatment A (no microplastics), Treatment B (0.5 g/L microplastics), Treatment C (1.0 g/L microplastics), and Treatment D (1.5 g/L microplastics). The results show that increasing microplastic concentrations disrupt photosynthesis in seagrass seedlings, indicated by a decrease in chlorophyll content, which leads to reduced growth and lower survival rates in seedlings (Treatment D). Based on this study, it is suggested that higher microplastic exposure may prevent seedlings from developing into mature seagrass individuals.