All 18 UCI ProTeams are invited automatically and obligated to attend, with nine cyclists per team. Two UCI Professional Continental were announced well ahead of time, and . UCI rules normally limit races to a peloton of 200 riders, but the Giro received special dispensation for a 207-rider peloton, allowing a 23rd team. The three additional invited teams are , , and . Despite talk that ProTeam might be excluded to the doping scandals involving team members Riccardo Riccò and Ezequiel Mosquera, they were included pursuant to UCI rules.
The cyclists wore numbers from 1 to 229; the first team had numbers 1 to 9, the second team 11 to 19, etc. The exception to this rule was the , who wore numbers 150 to 158 instead of 151 to 159, thus giving Italian champion Giovanni Visconti the number 150, as in 2011 it is 150 years after Italy was unified in the Kingdom of Italy.
â¡ Died as a result of a collision