The practice of delineating areas that are more liable to pollution from anthropogenic sources has become an important issue in groundwater resources management and land use planning. In this study attempt was made to characterize the groundwater reservoirs (aquifer unit) vulnerability zones at Ipinsa and Okeodu area, southwestern Nigeria using geoelectrically derived GODA model in GIS platform. First, one hundred and two (102) geophysical  - vertical electrical soundings (VES) data was acquired with Schlumberger array using current electrode separation (AB/2) of 1 to 150 m. The acquired VES data were qualitatively interpreted to determine the area geoelectric parameters (layer resistivity and thickness). Applying the developed GIS – based GODA vulnerability model approach to the interpreted geoelectric parameters, the groundwater reservoir vulnerability index was estimated for the area.  Using the kriging interpolation technique, the GODA index results were used to produce the area groundwater reservoir vulnerability prediction map. The produced groundwater reservoir vulnerability map zoned the area into four vulnerable zones namely low, low – moderate, moderate and high categories. The estimated percentage areal coverage for the low, low – moderate, moderate and high vulnerable classes are 24 %, 43 %, 2 % and 31 %, respectively. The GODA model groundwater reservoir vulnerability prediction produced map show high significant qualitative correlation with the area geologic rocks. The information on the model map could be helpful for better management of groundwater resources in the study area and give planners and decision makers an opportunity to prepare appropriate groundwater investment plans.