The potential of water hyacinth (Eichhornia crassipes (Mart) Solms) as a bioacummulator/bioindicator of arsenic in dilute solution was investigated. Results show that in the absence of a high level of phosphate, it can remove arsenic effectively. However, in high phosphate concentration, arsenic uptake was inhibited. Arsenic could also be leached out from the plant. Hence caution must be exercised in interpreting the arsenic status of the aquatic environment as seen through water hyacinth.