Gob ventilation boreholes (GVBs) are widely used in United States underground coal mines for longwall gob degasification purposes. GVBs can recover 30 to 50% of methane emissions from the longwall gob depending on geologic conditions [1]. Generally, GVBs are considered useful for reducing methane concentrations in working areas, explosion hazards and creating safer working conditions for the longwall section. Computational fluid dynamics (CFD) modeling efforts at the Colorado School of Mines (CSM) under a National Institute for Occupational Safety and Health (NIOSH) funded research project have confirmed that gob ventilation boreholes are helpful to reduce the methane concentrations at the face. However, they may also draw fresh air from the face into the gob, creating explosive gas zones (EGZs) within the gob. GVBs operation may thereby increase oxygen ingress into the gob and create explosive gas mixtures. It is important to identify the locations for GVBs placement to maximize the methane extraction and to minimize any explosion hazards. In this paper, CFD studies will be presented to analyze the effect of GVBs design and operating parameters on methane extraction, formation of EGZs in the gob and methane concentrations at the longwall face and tailgate. The distance of GVBs from the tailgate and the working face, the borehole diameter, the distance from the top of the coal seam being mined, the wellhead vacuum pressure and number of GVBs operating on the panel all have a significant effect on methane extraction, explosive gas mixtures volume and methane concentration in working areas. CFD studies at the CSM identified optimal GVBs design and operating parameters, which can maximize the benefits and minimize the risks.