Claudio Marchisio gave the Azzurri an early lead but the European minnows fought back and drew level in the dying minutes through a Maxime Chanot header to secure a surprise result.
Despite the setback, Prandelli refused to label his side's performance a failure, although he did admit that his side have to improve between now and their tournament opener against England on June 14.
"This test was not an absolute failure," he told reporters after the game. "However, it is clear that we need to improve.
"This was a test we had to go through because we have played a few games and we know we are not brilliant. We trained until yesterday, but let's start with the belief that we can have a great World Cup."
The coach admitted his side are missing Riccardo Montolivo, who has been ruled out of the tournament in Brazil after picking up an injury in their draw with Republic of Ireland on Sunday.
"It's clear that we are missing someone who has been with us for so many years," said Prandelli.
"But at this time we need to consider other things such as the position of Candreva and I saw some other interesting things.
"Mario Balotelli had two good opportunities in the first half and had another chance when Antonio Cassano came on.
"We have missed a few chances and then conceded a goal from a corner, where our marking was completely wrong.
"We must also get better with our closing down because we have more players in midfield and less on the outside."