A groundwater quality assessment has been conducted to determine the suitability of the groundwater for various purposes. In June 2021, groundwater samples were obtained from 65 locations in the Mendha river basin, Rajasthan, India, and then analysed for a range of chemical parameters. About 30% and 43% of the samples exhibit higher TDS and fluoride values than the permissible limits. Approximately 83% of the samples had very hard water, with a total hardness (TH) above 300 mg/l. The trend of major cations is in the order of Na+ > Mg2+ > Ca2+ > K+, and major anions are in the order of Cl- > HCO3- > F- > NO3- > SO42-. The analysis of ionic ratio plots reveals that silicate weathering is the predominant geochemical activity in the study area. Statistical analysis shows that both natural and anthropogenic activities contributed to ionic enrichment in the groundwater. According to the water quality index, most of the study area has good to poor quality for drinking purposes. In the irrigation indices, the sodium absorption ratio (SAR) is mostly suitable, but sodium percentage (SP) suggests that over one-third of the samples pose sodium-related risks to soil health. Kelly's index (KI) reveals that most of the samples are classified as suitable. Permeability index (PI) and magnesium hazard (MH) indicate that a significant percentage of water samples categorized as unsuitable for irrigation could degrade soil permeability and structure in the long term. The basin exhibits a high salinity and low to very high alkali hazards. One-third of the basin's groundwater is classified as unfit for drinking and irrigation, emphasizing the necessity of regular monitoring and effective management strategies to mitigate hydrogeochemical contamination.