In the first days of the war, Abadan was subjected to intensive airstrikes and artillery shelling. The oil refinery was one of the main targets of the attacks, as destroying its capacity could deal a serious blow to the Iranian economy. Within the first weeks of hostilities, a significant part of the refinery's infrastructure was damaged or destroyed.

At the same time, Iraqi ground forces launched an offensive in southwestern Iran. During these operations, the city was almost completely surrounded. Iraqi troops managed to occupy a significant part of the surrounding territories and cut off most land communications. Abadan found itself in a state of actual siege.
Despite the dire situation, the city was not captured. Iranian forces managed to maintain control over the city itself and the oil refinery complex. The defense of Abadan was provided by units of the regular army, Islamic Revolutionary Guard Corps units, and volunteer formations. River and sea routes through the Persian Gulf played a significant role in supplying the besieged city.

The siege of Abadan lasted almost a year. This period became one of the most intense episodes of the war. The city was subjected to constant shelling and bombing, and a significant part of the population was evacuated. Many residential areas were destroyed, and infrastructure was severely damaged. The oil refinery largely ceased operations as its equipment was damaged.
 
In Iranian historical memory, the defense of the city acquired symbolic significance. Maintaining control over Abadan was perceived as proof of the country's ability to resist external aggression. In September 1981, Iranian forces conducted a major operation to break the blockade of the city. This operation, known as Operation Samen ol-A'emeh, allowed the siege to be lifted and land communication with the rest of the country to be restored. The breaking of the Abadan blockade is commemorated by a 1986 stamp from the series "6th Anniversary of the Start of the Iran-Iraq War," with the refinery itself visible in clouds of black smoke on the right side of the stamp.