Groundwater is a major source for drinking and agricultural purposes to most of the population in Udupi district, southern India. The objective of the current study is to evaluate the spatial distribution of major ions and drinking water quality index in the study area. Groundwater samples (N = 100) were collected during pre-monsoon season. The collected samples were analyzed for major cations and anions. Based on electrical conductivity, 90 open wells were classified as fresh (<1500 µS/cm), four open wells as brackish (1500–3000 µS/cm) and six open wells as saline (>3000 µS/cm). The evaluation of drinking water quality index identified that seven groundwater samples are good, four are poor, two are very poor, three are considered to be unsuitable for drinking and 84 groundwater samples are excellent for drinking purposes. Human health risk assessment revealed that infants were more vulnerable to health risk than other age groups. The concentrations of nitrate in the two open wells were above the prescribed limit (>45) which could cause human health risk for all the age groups. Water management plan in the study area should prioritize to reduce the nitrate contamination in the study area.