The battle was fought at the bank of Metaurus River, the exact site of the battle is uncertain; tradition places it between Fossombrone and the Furlo, but it is probable that it occurred nearer the Adriatic coast. The exact numbers of troops on both sides are not known. The data given by the ancient sources are either insufficient or very contradictory. Appian for instance says that the Carthaginian force numbered 48,000 infantry, 8,000 cavalry and 15 elephants. Livy claims that there were more than 61,000 slain or captured Carthaginian soldiers at the end of the battle and there were still more who escaped the slaughter. These figures look inflated, especially when one compares them with the account left by Polybius. Modern estimates suggest Hasdrubal's army was about 30,000 in strength, and Marcus Livius' army of roughly equal numbers. According to Livy, 27.36. The propraetor L. Porcius Licinius commanded two legions - as many men as the consul. This means that Livius and Porcius had between them four legions - equal to 32,000-40,000 men, including their Allies. However, the numbers of the allied contingents could have been less than usual due to the refusal of some of the Roman clients to provide auxiliaries. The Roman force was probably further diminished by earlier fighting with Hasdrubal the evidence of which is the presence of several thousand prisoners in Hasdrubal's camp. About 7,000 troops accompanied Claudius Nero. Therefore, it is certain that Romans were significantly outnumbered. Carthaginians he lacked cavalry, of which the Romans had a substantial number.
Like most Carthaginian armies, Hasdrubal's was a mix of many different cultures and ethnicities, including Iberians, Ligures, Gauls and few were of African origins. Hasdrubal right flank was at River Metaurus and laft flank at a inaccessible hilly terrain. He placed his Cavalry at right wing to guard it against superior Roman cavalry that could out flank its right wing. Contrary to this Hasdrubal's left flank was well guarded by hills at left and ravines on front. Hasdrubal's best troops were Iberians, armed with shields and swords, made his right flank, along with the few African troops that he did have (not much is known about these troops - they may have been spearmen drawn from some Carthaginian territory, or from another part of Africa). The center was composed of Ligures who were not as well-trained as the men on his right flank. Finally, on his left, he placed the disorderly Gauls, who he hoped would be shielded by the intraversable terrain (a deep ravine) in front of them. Hasdrubal also had ten elephants in his army. Marcus Livius Salinator, placed the Roman army in front of Carthaginian force. Roman left wing was commanded by Marcus Livius, right wing was under Gaius Claudius Nero, facing the inaccessible Gauls and center was under the command of Porcius Licinus. Roman Cavalry was placed in front of Carthaginian cavalry at left wing.
The battle started with Roman left flank charging the Carthaginian right. followed a little later by Roman center. The outnumbered Carthaginian cavalry tumbled against the Roman cavalry. Carthaginian right wing and center, held the ground and the War elephants, before being overcome, initially succeeded in breaking the Roman lines and spreading mass confusion making the initial combat favorable to Hasdrubal. Claudius Nero at Roman right flank, struggled to overcome the terrain that blocked his path to the unprepared Gauls on Hasdrubal's left, and, seeing the futility in wasting further time attempting to reach them, instead took half of his men and led them from behind the battling Roman lines to the extreme Roman left, swinging his troops around and crashing into the Carthaginian right flank with sudden force and intensity. The Carthaginian right wing composed of Iberians, could not withstand this two prong attack, Marcus Livius from front and Claudius Nero at flank. They soon panicked and fled in confusion, collapsing onto the Carthaginian center and creating mass confusion, the disordered Carthaginian center faced a three prong attack, Porcius from front, Marcus Livius from flank and Claudius Nero from rear. By now Roman cavalry had completely defeated the Carthaginian cavalry and with the retreat of Carthaginian center a general retreat of Hasdrubal's army started. Romans chased the retreating Carthaginians and met almost no resistance from the unfit Gauls. Most of the Carthaginian casualties occurred during this disordered retreat. The Carthaginian general, seeing that there was nothing more he could do, and presumably doubtful of his own prospects of escape, or simply unwilling to be taken captive, charged into the thick of the nearly concluded battle and met a glorious, if pointless death.