After defeating the Prussian army in the autumn of 1806, Emperor Napoleon entered partitioned Poland to confront the Russian army, which had been preparing to support the Prussians until their sudden defeat. Crossing the River Vistula, the French advance corps took Warsaw on 28 November 1806.
The Russian army was under the overall command of Field Marshal Mikhail Kamensky, but he was old and becoming infirm. The Russian First Army of some 55,000 to 68,000 men, commanded by Count Bennigsen, had fallen back from the Vistula to the line of the River Wkra (Ukra), in order to unite with the Second Army, about 37,000 strong, under General Friedrich Wilhelm von Buxhoeveden (Buxhöwden), which was approaching from Russia and was still several days march from the First Army. However, realising his mistake in allowing the French to cross the Vistula, Kamensky advanced at the beginning of December to try to regain the line of the river. French forces crossed the Narew River at Modlin on 10 December, and the Prussian Corps commanded by General-Leutnant Anton Wilhelm von L'Estocq failed to retake Thorn (Toruń). This led Bennigsen on 11 December to issue orders to fall back and hold the line of the River Wkra.
When this was reported to Napoleon, he assumed the Russians were in full retreat. He ordered the forces under Marshal Joachim Murat – the 3rd corps of Marshal Louis Nicolas Davout, 7th Corps of Marshal Pierre Augereau, 5th Corps under Lannes, and Murat's 1st Cavalry Reserve Corps – to pursue towards Pułtusk. Meanwhile, Marshal Michel Ney's 6th Corps, Marshal Jean-Baptiste Bernadotte's 1st Corps, and Marshal Jean-Baptiste Bessières's 2nd Cavalry Reserve Corps turned the Russian right. Marshal Nicolas Soult's 4th Corps linked the two wings of the French army.
Kamensky reversed the Russian retreat, and he ordered an advance to support the troops on the River Wkra. On the night of 23 and 24 December, Davout's corps forced a crossing of the lower Wkra in the Battle of Czarnowo. After engagements at Bieżuń on 23 December with Bessières and Soldau (Działdowo) on 25 December with Ney, the Prussian corps under L'Estocq was driven north towards Königsberg. Augereau's corps seized a second crossing of the Wkra on the 24th at Kołoząb. Realising the danger, Kamensky ordered a retreat on Ostrołęka. At this time the old field marshal appears to have had a mental breakdown and returned to Grodno. Bennigsen decided to disobey his superior's orders by standing and fighting on 26 December at Pułtusk. He had available the 2nd Division of Lieutenant General Alexander Ivanovich Ostermann-Tolstoy, the 6th Division of Lieutenant General Alexander Karlovich Sedmoratski, part of Lieutenant General Dmitry Golitsyn's 4th Division, and part of Lieutenant General Fabian Gottlieb von Osten-Sacken's 3rd Division. To the north-west, most of the 4th Division commanded by Golitsyn and the 5th Division under Lieutenant General Dmitry Dokhturov fought the Battle of Gołymin on the same day.
The weather caused severe difficulties for both sides. Mild autumn weather had lasted longer than normal. The usual frosts, which rendered the inadequate roads passable after the muddy conditions of autumn, were broken by thaws. There was a thaw on 17 December and a two-day thaw on 26 and 27 December. The result was that both sides found it very difficult to manoeuvre; in particular the French (as they were advancing) had great difficulty bringing up their artillery. Davout recorded it took two hours to cover 2½ miles.
There were also difficulties with supply. Captain Jean-Baptiste-Antoine-Marcelin, Baron de Marbot, who was serving with Augereau's Corps wrote:
||It rained and snowed incessantly. Provisions became very scarce; no more wine, hardly any beer, and what there was exceedingly bad, no bread, and quarters for which we had to fight the pigs and the cows.
Pułtusk lies on the west bank of the River Narew with a suburb on the east bank. The road from Strzegociz crossed the river by a bridge and then ran north-west towards Gołymin. A second road from Warsaw entered the town from the south-west, and then ran along the west bank of the river towards Różan. Before it reached Pułtusk this road was joined by one from Nasielsk. Another longer route to Różan ran along the east bank. The final road was that to Markow, which ran northwards from the town. The town itself lay on low ground. To the north and west lay a plateau, narrowing to a wide ridge nearer the river. A ravine cut into the plateau near the river. A large wood lay on the north-west side of the plateau, towards the village of Mosin. Further out from the plateau more woods covered the approaches from Warsaw.