Turning to green technologies in wastewater treatment is a well-known global trend. The use of natural sorbents of plant origin or phytosorbents in order to purify water from various types of pollutants is becoming more and more popular. This solves several important problems at once: the use of harmless natural materials, reducing the cost of processing, and waste disposal. Moreover, there is a global increase in waste in the agricultural, food, woodworking, and other industries. This review presents data on the modern use of natural materials, mainly vegetable waste, as sorbents in wastewater treatment technologies. Natural materials remove ion metals, dyes, crude oil and petroleum products, and other organic and non-organic contaminants. The techniques of obtaining phytosorbents from plant raw materials are considered. The methods for activation and modification of the various phytosorbents, which provide greater sorption efficiency, are presented. The adsorption mechanisms for various water contaminants are examined, and model descriptions are shown. It has been revealed that the effectiveness of sorption interaction mainly depends on the presence of functional groups. Studies over the past twenty years have shown good prospects for the use of such materials and technologies in practice.