Abstract: Geoelectric investigation is carried out in the Sagar Island region to assess the prevailing groundwater condition. The Vertical Electrical Soundings (VES) are carried out in thirty-eight locations of South, Central and Northern parts of Sagar Island region to determine the subsurface hydrological conditions. Maximum current electrodes spacing (AB) of 1200 m are used. Four soundings were carried out near existing boreholes. A combination of curve matching techniques and computer iterative software are used for processing the data. VES results show mostly six layers and constitutes of topsoil layer, saline water, brackish water, impermeable clay layer, fresh water and bottommost clay with silt and fine sand lenses. The results of VES studies significantly correspond with the borehole data and a litho-resistivity relationship is established for this area. The diagnostic constant (A) calculated from the product of hydraulic conductivity and electrical conductance obtained from prescribed known value is used to find the aquifer conductivity and Transmissivity parameters in other locations under the similar hydrodynamic condition of the same region where no pumping test results of boreholes are available. Hydraulic conductivity values vary between 9.92 m day-1 at R8 to 13.56 m day-1 at R24. Transmissivity values also vary between 1687 m2 day-1 at R11 to 2868 m2 day-1 at R24.