Dataset provides information about major anions- chloride, sulphate and nitrate (in mg L-1) in the Lake Paione Superiore (LPS) at different layer depths along the water column collected at least twice per year (late summer/autumn) within the period 1984-2013. Sampling is performed at the deepest point of the lake. Winter or spring samplings are performed occasionally. The Lake is included in the monitoring sites of the UN-ECE Program ICP WATERS (International Cooperative Programme on Assessment and Monitoring of Acidification of Rivers and Lakes) funded by Italian Ministry of the Environment.