This method is for determining nickel, molybdenum, phosphorus and cobalt in fresh gamma-alumina supported catalysts; and nickel (Ni), molybdenum (Mo), phosphorus (P), cobalt (Co) and aluminum (Al) in fresh silica-alumina supported catalysts of known composition by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). The method is suitable for determining nickel over a range of 1 to 10 mass-%, molybdenum over a range of 5 to 20 mass-%, phosphorus (as phosphate only) over a range of 0.5 to 25 mass-%, cobalt over a range of 1 to 5 mass-%, and aluminum over a range of 5 to 50 mass-%. Catalysts containing alpha- or theta-alumina phases cannot be analyzed by the method. Nickel bearing catalysts that also contain tungsten are analyzed by UOP Method 924.