Failing to commit enough men forward in the face of a very deep-lying home defence, Inter failed to muster a clear-cut chance during a drab first half.
The visitors looked more threatening in the second period but still failed to really trouble the goal of Artur Boruc as they lost ground in the race for the last Champions League spot.
And, despite dominating possession for large periods of the match, the Nerazzurri could have left Tuscany empty handed had goalkeeper Cesar not turned Adem Ljajic's penalty around the post with just over 20 minutes left to play.
The Nerazzurri traveled to the Artemio Franchi still unbeaten under the stewardship of former youth team coach Andrea Stramaccioni, needing three points to keep them in the race for European football next season.
A 2-1 victory against Siena last weekend left the Nerazzurri six points off Lazio - who occupy the last Champions League place - with six games left to play, and they had to do without the services of the suspended defender Walter Samuel.
Fiorentina, just three points off the drop zone in 16th, were without suspended striker Carvalho Amauri as the Tuscan side looked to consolidate their top-flight status.
With avoiding the drop their chief ambition, the hosts showed limited attacking intent during the first half as they sat deep and frustrated Inter, who were restricted to shots from distance.
With a little under half an hour gone, the Nerazzurri carved out their clearest opening following a Viola break when Diego Forlan found space in the middle of midfield and picked out Mauro Zarate, who cut inside his man but dragged his effort wide of the post.
Having almost been caught on the break during a rare foray forward the hosts became even more conservative as the clock ticked to half time.
Committing more players forward come the second half, Inter looked a far more cohesive unit even before the introduction of Wesley Sneijder, but obvious chances were still at a premium.
Despite having more of the ball higher up the pitch, the Nerazzurri struggled with the final ball and continued in the pursuit of the lead with shots from distance.
And the visitors' European ambitions could have been dealt a fatal blow when Cesar felled Andrea Lazzari in the area but - Ljajic failed to convert from 12 yards, denied by a fantastic stop from the Brazilian.
The visitors still remain unbeaten under interim coach Stramaccioni but he will be disappointed by the inability to break down a stubborn defence and the dropped points could be pivotal come the shake up at the end of the season.