Sperm rheology is the study of its flow and deformation properties, essential factors in understanding sperm fertility and functionality. The objective of this study was to characterize the rheological behavior of human and animal sperm, with emphasis on viscosity, elasticity and their dependence on factors such as sperm concentration, pH and temperature. Measurements were performed using a controlled rotary rheometer, applying shear and oscillation tests to determine both Newtonian and non-Newtonian flow parameters and viscoelastic properties. The results indicate that sperm exhibits a predominantly pseudoplastic behavior, with viscosity decreasing with increasing shear rate, and viscoelastic components varying depending on the post-ejaculatory liquefaction state. The conclusions emphasize the importance of rheological parameters as potential indicators of sperm quality and their relevance in infertility diagnosis and assisted reproduction techniques.