Industrial production was up 0.7 percent compared with output in March - the first increase for three months - and it rose by 1.6 percent over 12 months in workday-adjusted terms, according to the National Statistics Institute (Istat). Economists had forecast a rise of 0.4 percent.
Paolo Mameli, senior economist at Intesa Sanpaolo, described the annual rise as "the best data for almost three years...in line with a return to GDP growth in the current quarter."
Italy's gross domestic product (GDP) declined by 0.1 percent in the first quarter - a hiccup in the country's efforts to emerge from a two-year long recession which it officially pulled out of at the end of 2013.
Despite the decrease, "the fairly positive domestic demand dynamic seen in the GDP results and unexpected industrial production results show the recovery is still ongoing," said economist at Citigroup Giada Giani.
"The negative GDP reading in the first quarter was probably a one-off," she said.
However, while the data suggest "a bit of a pick-up in the second quarter...the recovery is likely to remain weak," she added.
On Tuesday, leading indicators from the OECD (Organisation for Economic Cooperation and Development) also suggested that the momentum for growth in Italy was picking up, in line with the trend for the 18-member eurozone as a whole.