The commemoration will be held under the slogan "Vukovar, a place of special reverence".
The Battle of Vukovar, during which, according to data from the Vukovar Hospital, 1,624 Croatian soldiers and civilians were killed and 1,219 were wounded, started on 25 August 1991, when the former Yugoslav People's Army (JNA) and Serb paramilitary units launched an all-out artillery and infantry attack on the city which lasted until 18 November 1991, when the city's defence lines were broken.
According to hospital data, around 3,600 Croatian soldiers and civilians were killed in the aggression on and subsequent occupation of the city.
The besieged city was defended by around 1,800 members of the National Guard Corps, police and volunteers of the self-organised Croatian Defence Force (HOS), organised into the 204th Croatian Army Brigade.
After the ravaged city fell into the hands of the JNA and Serb paramilitaries, around 22,000 local Croats and members of other ethnic groups were expelled and several thousand Croatian soldiers and civilians were taken to Serb-run prison camps.
Numerous crimes were committed against the defence forces and civilians, including the massacre of 200 soldiers and civilians from the Vukovar Hospital who were taken from the hospital on November 19 and killed at a former farm at Ovcara, outside the city, and were buried in a mass grave.
Honouring the city's tribulations, the Croatian parliament in 2009 declared November 18 Vukovar 1991 Remembrance Day.
This year's commemorative events started on 11 November and will end on 18 November with the central commemoration to start outside the Vukovar Hospital.
Parliament Speaker Josip Leko on Monday visited Vukovar to lay wreaths and light candles at the Homeland War Memorial Cemetery, the Ovcara farm and the grave of Blago Zadro, commander of the 204th Brigade's 3rd Battalion.
The parliament said in a statement that the reason why Leko paid his tribute to soldiers and civilians killed while defending the city on Monday was because he would travel to Qatar for an official visit on Tuesday.