The majority of meningiomas is classified as grade 1 and typically follows a benign course. However, when morphologically grade 1 meningiomas invade adjacent brain tissue, they are reclassified as the World Health Organization (WHO) grade 2 tumors, which worsen the prognosis. Tumor cell invasion into adjacent structures requires extracellular matrix (ECM) degradation and diminished intercellular adhesion. Matrix metalloproteinase 9 (MMP9) is a key protein involved in ECM degradation, while E-cadherin plays a critical role in maintaining intercellular adhesion. This study aims to compare the immunohistochemistry (IHC) expression of MMP9 and E-cadherin in morphologically grade 1 meningiomas with and without brain invasion and to assess the correlation between their expression and brain invasion. An analytic observational study with a cross-sectional design was conducted using formalin-fixed, paraffin-embedded tissue samples from patients diagnosed with grade 1 meningiomas at Dr. Soetomo General Academic Hospital. The study included 43 subjects, divided into two groups: meningiomas with brain invasion (n = 20) and meningiomas without brain invasion (n = 23). IHC staining for MMP9 and E-cadherin was performed, and expression levels were evaluated using the H-score system. Statistical analysis was conducted using the Mann-Whitney test. No significant difference in MMP9 expression was observed between the two groups (p = 0.08), although a trend toward higher expression was noted in meningiomas with brain invasion. In contrast, E-cadherin expression was significantly lower in meningiomas with brain invasion compared to those without (p < 0.001). Decreased E-cadherin expression is strongly associated with brain invasion in grade 1 meningiomas and may serve as a predictor of this aggressive behavior. While MMP9 expression did not reach statistical significance, the observed trend warrants further investigation. These findings highlight the potential role of E-cadherin in meningioma progression and its utility as a prognostic marker.