Synthesis and evaluation of the bioactivity of spiroheterocycles (STC) against Trypanosoma cruzi are described. Selectivity indices were improved for two compounds versus the leads 17 and 20, the spiro-thiochromanone (STC) derivatives 17–26, thus increasing the therapeutic interest of our family. As our previous studies conducted on the structure of pharmacophore sites of our compounds made us hypothesize the existence of original sites, STC can be considered as promising tools further anti-trypanosoma studies, as probes for affinity chemotherapy. Compounds 17 and 20 are more potent and more selective than benznidazole and nifurtimox.