A dataset of 57 groundwater samples from springs discharging in the Nordeste Volcanic Complex (São Miguel, Azores) was compiled following a field survey. Waters are cold (7.9 – 16.6ºC), present a low mineralization (electrical conductivity between 56 and 200 µS/cm) and are mainly from the sodium chloride and sodium bicarbonate types. Major ion chemistry variation according to discharge altitude shows that electrical conductivity, as well as Cl- and Na+ content, decreases with altitude suggesting the contribution of sea salts spraying to groundwater composition.