Water, as a vital resource, plays a crucial role in human activities, notably in the textile industry, whose operations can significantly impact the quality of this resource. It is imperative to explore solutions, such as the adoption of advanced oxidative processes, which encompass the degradation of dyes present in effluents through the action of hydroxyl radicals. To evaluate the effectiveness of this treatment, acute phytotoxicity tests are carried out to analyze the responses of plant organisms to the effluents. Therefore, this study aimed to assess the acute phytotoxicity of a natural textile effluent subjected to heterogeneous photocatalysis and homogeneous photo-fenton treatments. Acute phytotoxicity tests were performed with cucumber (Cucumis sativus) and radish (Raphanus sativus) seeds, both for the treated effluent and in natura. The results revealed a sensitivity of cucumber seeds to effluent in natura and resistance to radish seeds. Regarding the phototreated effluents, the results showed an increase in seed germination rate and contributed to enhance this germination. Phytotoxic tests were also carried out with sodium chloride and sodium sulfate, and the toxicity of these substances to cucumber and radish seeds was confirmed.