Phyllanthus emblica (PE) is known to exhibit various pharmacological properties. This study aimed to evaluate the antimetastatic potential of a PE aqueous extract. Cytotoxicity to human fibrosarcoma cells, HT1080, was determined by viability assay using the 3-(4,5-dimethylthiazol,2-yl)-2,5-diphenyltetrazolium bromide (MTT) reagent. Cell migration and invasion were investigated using chemotaxis chambers containing membranes pre- coated with collagen IV and Matrigel, respectively. Cell attachment onto normal surfaces of cell culture plates was tested to determine the cell-adhesion capability. The molecular mechanism of antimetastatic activity was assessed by measuring the gene expression of matrix metalloproteinases, MMP2, and MMP9, using reverse transcription-polymerase chain reaction (RT-PCR) assay. The mRNA levels of both genes were significantly down-regulated after pretreatment with PE extract for 5 days. Our findings show the antimetastatic function of PE extract in reducing cell proliferation, migration, invasion, and adhesion in both dose- and time-dependent manners, especially growth arrest with low IC50 value. A decrease in the expression of both MMP2 and MMP9 seems to be the cellular mechanism for antimetastasis in this case. There is a high potential to use PE extracts clinically as an optional adjuvant therapeutic drug for therapeutic intervention strategies in cancer therapy or chemoprevention.