An in situ generated catalytic system based on PdCl₂ and sodium sulfate exhibited excellent catalytic activity in the Suzuki–Miyaura cross-coupling reactions of aryl halides with arylboronic acids at room temperature in water. A similar catalytic system can be obtained with PdCl₂ and sodium chloride or sodium acetate and is equally effective in Suzuki–Miyaura cross-coupling reactions. This method offers a mild and efficient alternative to the existing protocols since the reaction is proceeded in water at room temperature under ligand free conditions.