Alcohol use disorder (AUD) is a common disorder that affects people physically, emotionally, and mentally and can have long-term neuro-biological effects. Perineuronal nets (PNNs) are a type of condensed extracellular matrix that wrap around neurons in the central nervous system and control plasticity. AUD causes changes in PNNs, which affects neuronal plasticity. Previous studies showed increases in PNN density in female mice, which is associated with increased aversion-resistant drinking in female mice compared to male mice. Since studies have shown an increase in AUD among women, it is important to look at sex-specific mechanisms that may be involved. Previous research has shown that different phases of the estrous cycle in female mice are a possible indicator of variation in PNN intensity. This study tracked the estrous cycle in female mice and compared the numbers and intensity of staining of PNNs and PV neurons throughout the estrous cycle in the dorsal and ventral hippocampus. Understanding the relationship between the estrous cycle and PNNs is vital to providing insight into sex-specific mechanisms and treatments for AUD.