Wastewater and sludge are produced globally in large quantity. The lack of proper wastewater management has a direct impact on water quality and on the diversity of biological aquatic ecosystems. Vermifiltration is an earthworm-assisted process for the treatment of liquid and solid wastes with the use of a vermifilter. A vermifilter is constructed using different types of soil incorporated with earthworms that are capable of treating wastewater. The worm species, biomass, hydraulic retention time, hydraulic loading rate, type of wastewater, and seasonal variation greatly influence the performance of vermifiltration. In the alimentary canal of earthworms, enzymes and microorganisms synergize for considerable improvement in the decomposition of liquid/solid waste without sludge formation. The earthworm bulk densities per cubic meter (m−3) of bedding during vermifiltration assist in reduction efficiencies of 41%–89% (total nitrogen [TN]), 46%–86% (NH4+–N), 34%–74% (NO3−–N), 3%–17% (total phosphorous [TP]), 18%–38% (ortho-P), 35%–66% (total solids [TS]), 90%–95% (total suspended solids [TSS]), 88–92% (biochemical oxygen demand [BOD]), 80–90% (chemical oxygen demand [COD]), and 90–92% (total dissolved solids [TDS]) and reduction of pathogens that is evident with no odor formation after vermifiltration. Heavy metals are also reduced when a specific metal-binding protein, metallothionein, inside the chloragogenous tissue links heavy metals to form protein–metal complexes that can accumulate in the tissues of earthworms. The advantages of vermifiltration technology over conventional systems of sewage treatment are a low-energy system, a source of animal feeds, no formation of sludge, and an odorless system. It is recommended that vermifiltration that is environmentally friendly be used in the treatment of wastewater for being cost-effective without the production of sludge and odor as compared to conventional methods.