Aim:Infertility, defined as the inability to achieve pregnancy after one year of regular, unprotected sexual intercourse, is categorized as either female or male infertility. Male infertility is often associated with impairments in sperm quality and function. Heat shock proteins (HSPs), particularly HSP70, play a critical role as molecular chaperones, protecting cells from stress-induced damage by stabilizing proteins and ensuring proper folding. However, the relationship between HSP70 expression and male infertility has not been fully elucidated. This study aimed to investigate HSP70 expression in sperm samples from individuals with normal, oligozoospermic, and severe oligozoospermic profiles using immunocytochemical techniques.