An investigation was carried out to assess the water qualities and extents of impurities in groundwater and surface water (Padma river water) in Rajshahi City area. Water samples from a total of 330 tube wells and five spots of the river Padma were analysed for physicochemical, biological and hydrological parameters with standard methods. Among all considered parameters of ground water, concentrations of arsenic, iron, manganese, total hardness, and total coliform and faecal coliform bacteria were found above the permissible limits for potable water. In case of the river Padma, biochemical oxygen demand, chemical oxygen demand, total coliform, faecal coliform and suspended solids exceeded permissible limits. Both ground and river water must be treated properly before distribution for drinking purpose. Finally, the Padma is recommended as the most sustainable drinking water source for Rajshahi City Corporation area.