Dunaliella tertiolecta is a species of green microalgae known for its high performance in the production of biotechnological bioactives, in particular antioxidant and anti- tumor activity. Among these bioactives are lectins, which stand out in controlling tumors by activating the intrinsic and extrinsic apoptosis pathways and stimulating the production of regulatory proteins and genes. Lymphoma is one of the types of tumors with the most common mortality in men and is associated with socioeconomic issues, affecting mainly low-income countries, making it difficult to access diagnosis and treatment. The aim of this study was therefore to purify, biochemically characterize and evaluate the antitumour potential in lymphomas of the lectin extracted from Dunaliella tertiolecta. The lectins were extracted using magnetic stirring in PBS buffer pH 7.15 (0.01M) over a four-hour period. The extract was then centrifuged and the supernatant was precipitated using absolute ethanol (-20°) and subjected to ion exchange chromatography (DEAE Sephadex). The fraction with the highest activity was characterized with regard to specificity for blood types A and rabbit, the effect of temperature and inhibition by the presence of ions. The cytotoxic activity of the purified fraction was analyzed in U937 non-Hodgkins lymphoma cells and in healthy PBMC cells. The lectin showed stability at temperatures of up to 70° for 30 minutes and only the CaCl2 ion completely inhibited the activity of the lectin in blood A. The lectin showed satisfactory cytotoxic activity,being able to cause cell death after 48 hours of incubation in tumor cells and showed only 36% tocicity in healthy cells using twice the highest dose used in lymphoma cells. It is possible to state that the Dunaliella lectin has shown potential in the cytotoxic control of neoplastic lymphoma cells, as well as presenting biochemical characteristics that make it attractive for future biotechnological investigations.