General election candidates have been warned over texting, emailing and cold-calling voters.
About 60 people complained to the Data Protection Commission after the 2007 Dail election and 2009 local elections, the office revealed.
Would-be TDs and councillors had been given voters' names, addresses, emails and phone numbers, mainly by GAA and rugby clubs, and from friends and work colleagues.
Deputy commissioner Gary Davis said officials wanted to avoid a repeat, with an election expected within a month.
"In the interests of good relations with the electorate, I urge parties and candidates to abide by these simple guidelines in the course of the forthcoming election," he said.
"We're trying to nip it in the bud."
Mr Davis said there was evidence that all political parties had accessed personal details of voters unfairly.
"They all have form," he said.
Despite the warning, Mr Davis said no politicians can be prosecuted for sending unsolicited texts and emails or making phone calls as they are exempt under the legislation.
Political parties, however, can be held responsible along with the third party who has released the information. No enforcement orders or fines were issued after clubs were exposed for giving out people's details.
One school principal was investigated for sending unsolicited texts to parents.
The Data Protection Commission urged candidates not to attempt to obtain or use contact information from third parties and to avoid sending electoral messages unless to party members.
There were 50 complaints from the 2009 local election, ten from the 2007 campaign and two following the Donegal South West by-election late last year.
Commissioner Billy Hawkes has written to political parties with warnings about communicating directly with voters.
The Fine Gael website sparked one complaint to the commission after it collected phone numbers, email addresses, IP addresses and constituency location information from people commenting on the site. The database was subsequently hacked and personal details of 2,000 people accessed.
Meanwhile, the Union of Students of Ireland (USI) called on all parties to ensure that the looming election be held on a Friday to allow students to vote.
USI president Gary Redmond said: "Ideally, all elections should be held on Saturday as is common across the rest of Europe.
"The general election needs to be accessible for the students of Ireland, who are the future taxpayers of this country and will be burdened with paying for the bank bailout and the IMF loan."