Bentonite is highly colloidal clay, which hydrates in water and greatly increases viscosity. Among others, it is added to fresh water mud to increase hole cleaning capability, reduce filtration into permeable formation, form a thin filter cake of low permeability and promote hole stability. However, up till date in Nigeria, most of the bentonite in use in oil field operations had been imported. Attempts to use the local bentonite had yielded little or no result because of its low yield and inability to meet up with API specification. This work details an investigation of the constituents of the local Bentonite and a comparative performance evaluation with imported sample. Results of chemical analysis of both the imported and local bentonite indicated that the Nigerian Bentonite is predominantly Calcium based exchange cation while the imported sample is sodium based. This accounts for the high yield and faster hydration capabilities obtained with the imported sample than the local sample. Therefore, the local Bentonite needs to be beneficiated to API Specification before it could be used. The research work was able to achieve API standard of beneficiated local Bentonite that could be used as a suitable substitute in Nigeria for imported grade. This will no doubt provide a significant logistical improvement, home-base technological advancement, and substantial cost-savings and help meet up with local content aspirations.