The circulation of Monterey Bay is both variable and complex, and is likely to be significantly influenced by circulation in the adjacent California current. To study this circulation a two-layer, numerical model was used. The model was forced by inflow and outflow at an open boundary that connected the Pacific Ocean with the bay. Topography representing Monterey Canyon was included in the lower layer of the model. The effects of wind and tidal forcing were not considered. Results indicate that surface circulation is strongly constrained by topography when the lower layer flow is 5 cm/sec or larger and that the flows within the bay are consistent with geostrophic, vorticity-conserving flow over bottom topography. The sensitivity of the model to the distribution and strength of inflow and outflow forcing location was investigated. The model was found to be sensitive to the location of inflow and outflow forcing and also to the inflow and outflow vertical structure. Keywords: Ocean currents; Mathematical models; Submarine canyons; Bay bottom topography; Two layer ocean model.