Nanomedicine has led to the development of new biocompatible and biodegradable materials able to improve the pharmaceutical effect of bioactive components, broadening the options of treatment for several diseases, including cancer. Additionally, some snake venom toxins have been reported to present cytotoxic activity in different tumor cell lines, making them an auspicious option to be used as cancer drugs. Our research team has been working with the synthesis process and characterization of different polymeric nanoparticles to evaluate their antiproliferative activity in different cancerous cell lines. Chitosan nanoparticles (~400 nm, zeta potential: ~25 mV) had en encapsulation efficency (EE%) of ~50% of the black-tailed rattlesnake, and an IC₅₀ of ~15 µg/mL in the T-47D breast carcinoma cell line. Additionally, we have synthetized and characterized PLGA nanoparticles (~250 nm, zeta potential: ~-25 mV) with an EE% of ~90%. Rattlesnake venoms from the Sonoran Desert in Mexico have the potential to be developed into cancer pharmaceuticals, and, the addition of said venoms into nanoparticles has an interesting potential as a safe drug delivery method.