The figures (to 31 March of this year) show sales dropped from €3.67bn, while incoming orders were also down 20%, to €2.90bn from €3.65bn the year previous.
Heidelberg's decline in orders continued sharply into the fourth quarter, down 43% to €474m, compared to €825m in the same quarter for the year previous.
Restructuring costs of nearly €180m impacted the manufacturer's EBIT-based operating result, which came in at minus €228m from a positive €268m last year.
Disregarding the cost of Heidelberg's restructuring programme, EBIT weighed in at minus €49m, while the company reshuffle is expected to achieve cost savings of nearly €380m for the year 2009/2010.
Around 1,400 jobs have been cut since the start of the financial year 2008/2009, with overall employee levels standing at 18,926 at the beginning of April. However, the company is looking to shed 5,000 roles in total.
According to Bernhard Schreier, chief executive at Heidelberg, by implementing cost-cutting measures, the manufacturer "responded quickly to the difficult situation" and is witnessing the first signs of success.
He added: "For example, we recorded a positive free cash flow in the fourth quarter and have significantly reduced our inventories in the last few months."
During the fiscal year, Heidelberg recorded a positive cash flow of €76m and also cut its net debt by €72m to €657m in the fourth quarter. In addition, inventories were reduced by €177m to €1.03bn.
Schreier said: "As the market leader, we are able to maintain – and even extend – our considerable competitive advantages in this time of crisis, which promises good prospects for growth when the economic climate brightens."
Heidelberg sales fall by 18% in 2008
Heidelberg has cited a large drop in orders from the mechanical engineering sector as a key catalyst behind an 18% dip in sales to 2.99bn euro (2.6bn) for the financial year 2008/2009.