HTLV-1 can cause life-threatening diseases for which there are no effective treatments. 32 Prevention of HTLV-1 infection requires massive testing of pregnant women, blood for 33 transfusion and, organs for transplantation as well as safe sex. In this context, serological 34 assays are widely used for monitoring HTLV-1 infections. Despite the necessity of 35 recombinant antigens to compose serological tests, there is little information available on 36 procedures to produce recombinant HTLV1/2 antigens for serological diagnostic purposes. 37 In this work, we tested a series of genetic constructions to select those more amenable for 38 production in bacterial systems. To overcome the constraints to express sections of viral 39 envelope proteins in bacteria, we have used the p24 segment of the gag protein as a 40 scaffold to display the immunogenic regions of gp46 and gp21. Nine recombinant antigenic 41 proteins derived from HTLV-1 and five derived from HTLV-2 were successfully purified. The 42 HTLV-1 antigens showed high efficiency in discriminating HTLV-positive from HTLV43 negative samples using ELISA. Interestingly, HTLV-1-positive samples showed a high level 44 of cross-reaction with HTLV-2 antigens. This finding is explained by the high sequence 45 conservation between the structural proteins of these two highly related viruses. In 46 summary, the results presented in this work provide a detailed description of the methods 47 used to produce recombinant HTLV-1 and HTLV-2 antigens and demonstrate that the 48 HTLV-1 antigens show strong potential for serological diagnosis of HTLV1 infections.