The study of hydrogeochemical processes using rare earth elements was carried out using water samples from weathered basement aquifers in Oban Massif and environs. A total of only 29 as number water samples were collected from boreholes, streams, springs and river sources. Physical parameters (pH, Eh, Ec, TDS and turbidity) were measured insitu using standard equipments. Anions (NO3-, SO4 2-, HCO3-, PO4 3-, Cl-) were measured in the laboratory using titration and chromatography, major cations (Mg2+, Ca2+, K+, Na+) were analysed using inductively coupled plasma argon emission spectrometry while the rare earth elements were assayed using inductively coupled plasma mass spectrometry. Speciation modeling for solution complexation and saturation indices was done using the software VISUAL-MINTEQ3. 1. Results showed that low to medium pH (5.61-7.20) range and Fluorine mean value 20.08 ppm is common in the area which are not within WHO (2006) recommended values of 6.5-85 and 1.5 respectively for potable water. Rare earth elements exhibited very low values with exception of Ce (0.98 ppb), Gd (0.13 ppb), La (0.56