"Dear Silvio, I am sorry to make things difficult for you, but you are ignoring the poor people of the world," he told a German daily, Frankfurter Rundschau this week.
Gates said Italy was on his "shame list" and added that in an annual report issued by his charity organisation Gates Foundation, Italy's aid was listed 0.11 per cent of GDP in 2009 as against 0.21 per last year.
Gates described this contribution as "uniquely stingy among European donors."
Gates, who also co-chairs the Gates Foundation that gives billions of dollars for health and education programmes worldwide, mocked Berlusconi for shelling out money for a hair transplant in the German press.
"Rich people spend a lot more money on their own problems, like baldness, than they do to fight malaria," Gates told Süddeutsche Zeitung, another German daily.
The European media reported last week that following a hair transplant surgery, 73-year-old Berlusconi appeared with a complete thatch of hair. But, two days later the Italian premier was seen with another bald patch.
Gates captured headlines with his announcement at the World Economic Forum in Davos that his charity would give USD 10 billion for research and development of vaccines over the next decade to try and save the lives of 8.7 million children.
The UN described this donation as "unprecedented."
"The Gates Foundation's commitment to vaccines is unprecedented, but needs to be matched by unprecedented action. It is absolutely crucial that both governments and the private sector step up efforts to provide life-saving vaccines to children who need them most," said Margaret Chan, head of the World Health Organisation.