Fifty-five people died in the workplace last year, a 15% rise on the number of reported deaths in 2010.
The Health and Safety Authority (HSA), which has launched graphic new awareness campaigns featuring a farmer who lost his arm in a meat chopper, said agriculture was the most dangerous occupation.
Some 22 people were killed on farms compared with 25 the previous year, while eight workers in transport and storage business died, up from three in 2010, and six people died on building sites.
Martin O'Halloran, HSA chief executive, said due to the high number of agriculture-linked deaths there are now more inspections and awareness campaigns for farmers than ever.
"This is the second year in a row that the total number of workplace fatalities has increased," he said.
"The fact is that behind these statistics there are human tragedies, lives lost and families ruined. Everyone has the right to go to work without danger to their safety or health."
Forty-eight people died while working in 2010, according to accidents reported to the HSA.
The latest awareness campaign aimed at farmers has been launched in the media and carries a hard-hitting message through graphic television and radio ads.
The ad features Norman Bradley, a 46-year-old farmer from Fenagh, Co Carlow, who poses without his prosthetic limb. He lost his left arm after it was trapped in a meat-chopping machine 12 years ago. The shock tactic is aimed at encouraging farmers not to take risks.
Mr O'Halloran said further initiatives, awareness-raising campaigns and focused inspections are planned throughout 2012 aimed at achieving a sustained reduction in workplace accidents and deaths.