The tournament director also made the decision to reduce the event to 54 holes as the weather was showing no signs of improvement at the Olgiata Golf Club in Rome.
Round 2 of the 59th Italian Open Telecom Italia is now scheduled to begin Saturday with the same starting times as Friday.
Englands Ian Poulter holds a three-shot lead on 11 under par after an opening round of 61.
Padraig Harrington, looking to take over the top spot on the European money list, posted an opening round 1-under 71, 10 strokes off the lead.
Full-field scoring from the Italian Open