Study area: The study was conducted in Mymensingh sadar upazila covers an area of 388.45 km2, located in between 24°38' and 24°54' N latitudes and in between 90°11' and 90°30' E longitudes. The elevation from the mean sea level of the study area is 19 m. The climate of the study area is moderate, much cooler than Dhaka, as it is closer to the Himalayas. The temperature drops below 15 °C in winter which is spread over December and January, and the highest temperature is felt during April - May period, when the temperature may be as high as 40 °C. The annual average rainfall is 2,249 mm (Wikipedia, 2019). As Mymensingh sadar upazila is located in Madhupur Tract, the soil type of the study area is clayey texture and contains a large quantity of iron and aluminum, which are highly aggregated. The pH value of the soil of the area ranges from 5.5 to 6.0. The predominant land use of this area is Aus, T. Aman, Jute in Kharif season and Mustard, Wheat, Pulses, Potato, Onion, etc. in Rabi season. Data collection: The study was conducted by using historical data of various meteorological parameters (maximum and minimum temperature, rainfall, humidity, wind velocity, sun hours and solar radiation) over the period of 2006 - 2015. The required data were collected from the weather station, Bangladesh Agricultural University (BAU), Mymensingh, Bangladesh for the study area. These data were used to estimate the GW recharge and ET. Missing data in time series were estimated using the arithmetic mean of the adjacent month (Backundukize et al., 2011). Methods for GW recharge and evapotranspiration estimation: Soil-moisture balance method was used to estimate GW recharge. In this method, the concept of the water balance of the unsaturated zone (Thornwaite and Matter, 1957) was applied. Applying continuity at the soil surface, a balance equation can be written as:P = I + E + RO....(1); Mathematically, the balance equation of the soil moisture zone can be expressed by the following equation: I – ET – R = ± SM...... (2); From the above two equations, R ± SM = (P – RO – E) – ET or, R ± SM = P – RO – (E + ET) or, R ± SM = P – RO – AET.... (3) Where, AET = (E+ET) i.e. Actual Evapotranspiration, E = Evaporation, ET = Evapotranspiration, I = Infiltration, P = Rainfall, RO = Runoff, R = Recharge, and SM = Change in soil-moisture. The soil-moisture, at the beginning of a period (day or month), is illumined by runoff and diminished by the AET for the period. When ?SM becomes negative it represents an increase in soil moisture deficits (SMD), when SMD develops no recharge occurs according to this concept. In this method, when SMD within the soil zone is fully satisfied i.e. SMD = 0, then only the excess i.e. positive SM represents partial recharge to the saturated zone i.e. aquifer. According to the soil moisture balance method, when ?SM is positive, then the only recharge occurs (Rushton and Ward, 1979). Therefore, according to the principle of soil moisture balance, GW recharge to the aquifer becomes, R = P – RO – AET..... (4). For the above equation, AET was estimated from the PET, calculated from CROPWAT-8.0 model using all the previously mentioned meteorological parameters (minimum temperature, maximum temperature, humidity, wind speed, and sun hours), and runoff was determined using a standard method. After estimating AET and direct runoff, GW recharge was calculated by using the soil moisture balance method for the study area.