There are many fresh water inputs to the Black Sea that differ significantly from each other in terms of both the water level and the extent of the river basin. Seasonal distributions of dissolved metal/metalloid concentrations were measured using Inductively Coupled Plasma Mass Spectrometer (ICP-MS) in 13 rivers (Kizilirmak, Yesilirmak, Melet, Pazarsuyu, Aksu, Harsit, Degirmendere, Solakli, iyidere, Buyukdere, Firtina, caglayan, and Kapistre) discharge of waters to Eastern Black Sea coast of Turkey and the results were compared in this study. The highest mean levels were found as aluminium (Al): 174 mu g/L, chromium (Cr): 1.02 mu g/L, manganese (Mn): 56 mu g/L, copper (Cu): 3.2 mu g/L, lead (Pb): 0.37 mu g/L in Melet and iron (Fe): 130 mu g/L, arsenic (As): 3.9 mu g/L, antimony (Sb): 2.2 mu g/L in Yesilirmak and cobalt (Co): 0.20 mu g/L, nickel (Ni): 3.4 mu g/L, molybdenum (Mo): 1.5 mu g/L in Kizilirmak rivers. The highest mean concentration of zinc (Zn): 68 mu g/L was determined in Degirmendere and the highest mean cadmium (Cd) concentration (0.29 mu g/L) was measured in Harsit. The lowest average Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, and Pb concentrations were detected in the caglayan. The rivers were grouped in three separate groups according to PCA analysis. The abundance of As, Ni, Co, Sb, Mo, Cr elements were higher in the first group of rivers characterized by a large river basin, while the abundance of Al, Mn, Zn, Cu, Pb elements was higher in the second group of rivers with high erosional effect. The average manganese (Mn) profile in the Melet has been identified as above the legal limits for drinking water determined by Environmental Protection Agency (EPA) and European Commission (EC). The Yesilirmak in terms of antimony (Sb), and the Yesilirmak and the Kizilirmak in terms of arsenic (As) and nickel (Ni) differs greatly compared to other rivers. The highest average Sb concentration had been identified in autumn. Arsenic concentrations of the Kizilirmak and the Yesilirmak were higher than other rivers in all seasons. It has been determined that the extent and geological structures of the river basins and erosional transport play an important role in the classification of rivers in terms of metal/metalloid contents. It has also been shown that knowing the spatial and temporal changes of the water quality of rivers is essential for future projections and protection.