The organisation published newspaper adverts on Tuesday calling on its followers to vote in the election in the first sign the group is making the vote a high priority.
Mahmud Zahhar, a Hamas leader, told al-Hayat newspaper Hamas would contest legislative and presidential elections - the first time Hamas has made such a commitment.
"We want free, honest and clean elections that everybody accepts," he said.
Hamas boycotted the 1996 polls for the Palestinian Legislative Council and presidency on the grounds they were not free and participation would have legitimised the 1993 Oslo Accords.
Analysts say a strong Hamas campaign could pose a formidable challenge to Palestinian president Yasir Arafat, although Hamas is expected to stop short of trying to unseat him.
Khalid Amayreh, Aljazeera's correspondent in the West Bank, says Hamas has been weakened militarily by Israel, but its political popularity has grown.
He said opinion polls indicated 30% of Palestinians would vote for the resistance organisation – largely because it is seen as fighting Israeli occupation.
And Azzam Tamimi, a Palestinian academic, told Aljazeera.net Hamas would do very well if the elections were free and fair.
"They are the most popular party in Palestine today," he said. "Hamas has been vindicated by the failure of the peace process with Israel which it condemned from the start.
"They are the most popular party in Palestine today. Hamas has been vindicated by the failure of the peace process with Israel ... and it has lived up to its pledges and commitments to the Palestinian people"
"And it has lived up to its pledges and commitments to the Palestinian people."
But Tamimi said Hamas accepted it would be imprudent to take the reins of power.
"They have accepted the international community will not allow them to take power. If they do so they would be treated as a pariah and that would not be in the Palestinian national interest.
"So they will go for the second best option and that is to get true representatives of the people who will be clean and uncorrupt into positions of power and influence."
Branded a terrorist group by Israel and western countries, Hamas is seen by its supporters as a legitimate force defending Palestinians from a brutal military occupation.
Hamas accepts Yasir Arafat's
position as Palestinian leader
The group's short-term aim is to drive Israeli forces from the Occupied Territories, and its long-term goal is to establish an Islamic state on all of historic Palestine.
Hamas is divided into two main spheres of operation – a military wing which carries out attacks against Israelis, and a social wing which builds schools, hospitals and religious institutions.
Yasir Arafat, who heads the secular Fatah group, announced plans earlier this month to hold municipal elections in December.
He has also promised to hold a general legislative and presidential vote, but has not set a date.
The promises came in response to widespread discontent over his corruption-plagued government and chaos in Palestinian areas.
Israeli occupation has cast doubt
over Palestinian elections
However, Aljazeera's Amayreh said he would not be surprised if Arafat decided to delay the votes.
"Free and fair electons are not possible at the moment because of Israeli occupation of Palestinian areas," he said.
"Ultimately it is not up to Arafat anyway because it is the Israelis who control the streets. And it is not in Israel's interests to have credible elections in Palestine because that would empower the Palestinian people."