The increase of the global population and the requirement of food production and agricultural development, combined with a lack of water resources, have led to human attention being drawn to unconventional water sources, including saline water and wastewater. Most unconventional water treatment methods are not cost-effective; however, researchers have become interested in the phytoremediation method due to its cost-efficient and eco-friendly removal of many pollutants in recent years. Research showed that due to its unique characteristics, vetiver grass can be useful in phytoremediation. In the current review, research on vetiver-based phytoremediation of unconventional water, especially wastewater, was reviewed. The vetiver-reduced contaminants in wastewater can be related to the interactions between (1) the root-released oxygen into the rhizosphere; (2) the root-based uptake of nutrients from the wastewater; (3) the existence of an appropriate surface area for the attached microbial growth; as well as (4) the root-exuded organic carbon.