This research aimed to verify the domestic wastewater toxicity in different treatment stages through phytotoxicity tests with lettuce (Lactuca sativa L.) and cucumber (Cucumis sativus L.) seeds.Therefore, the stages of a domestic sewage treatment plant were assessed according to the sampling points: the affluent (raw sewage), the UASB Reactor effluent and the effluent (treated sewage).The samples were submitted to chemical analysis, and the bioindicators, to the phytotoxicity test.The domestic wastewater in the three stages of treatment of the plant were characterized as non-phytotoxic to the bioindicators analysed (p<0,05); however, there was a significant decrease of Germination Index in the effluent treated for lettuce seeds and in the UASB Reactor effluent treated for cucumber seeds.It was possible to conclude that the domestic effluents generated during the treatment stages can be disposed in the environment because they do not present potentially toxicological risks.