The IHS Markit Purchasing Managers Index (PMI) slipped to 47.4 in March from 47.7 in February, falling further below the 50 mark that separates growth from contraction.
The reading was the lowest since May 2013 and matched the median forecast in a Reuters survey of nine analysts.
Italy fell into recession at the end of 2018, with gross domestic product falling 0.1 percent in each of the last two quarters. Some recent data has been more positive, but the PMI suggests the manufacturing sector continues to struggle badly.
IHS Markit said its sub-index for new orders at manufacturers fell in March to 44.9 from 46.1 the previous month, remaining below 50 for the eighth straight month and registering the lowest level since April 2013. - Detailed PMI data are only available under licence from His Markit and customers need to apply for a licence.