The latest opinion polls have given Olmert's party a strong lead over its Likud and Labour challengers.
"We are not going to be able to fulfil all our dreams," Olmert said in an opinion piece for the top-selling Yediot Aharonot newspaper.
"We must preserve the main settlement blocs in Judea and Samaria [the West Bank] and we will fix the route of the security barrier beyond which we will no longer remain."
All the settlements that Olmert has pledged to hold on to are on Palestinian land that was occupied or annexed in 1967.
The controversial separation barrier being erected across the occupied West Bank fences off the majority of the 250,000 Jewish settlers from the Palestinian population of 2.5 million.
Kadima is expected to emerge as the largest party in the election although it will need the support of other parties to ensure parliamentary approval for the implementation of the pullout plan.
Definite borders by 2010
The acting prime minister has promised to draw Israel's definite borders by 2010 if he is elected.
Since its foundation in 1948, Israel has not established defined borders.
Under the leadership of Ariel Sharon, the prime minister who has been in coma since early January, Israel unilaterally withdrew in August from the occupied Gaza Strip, though it kept control over the Palestinian territory's borders, air space and sea.