Ms Harman said privacy of candidates should be protected
Prospective MPs may no longer have to give their full address when standing for office, under plans being considered by the government.
While voters should know their MP lives locally, there was a question mark over whether they had to give house numbers or streets, Harriet Harman told MPs.
Tory MP Julian Lewis suggested giving part of a postcode may be sufficient.
In May the High Court ordered addresses to be published with expenses claims, but MPs voted to keep them private.
The High Court had ordered addresses be published as part of a wider Freedom of Information battle over expenses claims, to allow people to check MPs were living in properties they claimed for.
In its ruling it pointed out that "the addresses of well-known MPs like [Tony] Blair and [Margaret] Beckett were available in any event, and that every prospective MP would be registered as candidates and as electors, with names and addresses in the public electoral register."
But the government moved an order to exclude addresses, travel plans and security bills from Freedom of Information laws, to protect MPs and their neighbours from "harassment at home".
In the Commons on Thursday Mr Lewis, who led efforts to keep MPs' addresses from being published if there were security concerns, praised Commons leader Ms Harman for her "decisive intervention" in the High Court case.
He pointed out that the High Court's "dangerous decision" to allow addresses to be revealed was based on the fact they were published every four or five years anyway and asked: "Can we now consider closing this loophole?"
"The guidance from the information commissioner in situations of this sort is usually that the first part of the postcode is enough," he added.
Ms Harman, whose own home has been the target of protesters, said the issue was currently "under consideration by the Ministry of Justice".
"Obviously, it is in the public interest for the public to know when they come to be voting in an election whether or not the candidate lives in that area or whether they live somewhere miles away," she said.
"But whether or not there has to be the precise address of the flat number of the block in the particular street is questionable."
She said the government had to make sure voters "have the information they need" while ensuring MPs, candidates and their families "have the privacy they need".
"I'm sure we can work together as a whole House to make sure we can get this sorted out," she added.
A Ministry of Justice spokesman said: "Dr Julian Lewis MP raised the matter at second reading of the Political Parties and Elections Bill on 20 October and Michael Wills assured him that the government agreed to consider the matter with Parliament."