Reconstruction efforts have been heavily delayed -- largely due to red tape and a lack of funds -- and much of the city centre still lies abandoned.
Local archbishop Giuseppe Molinari celebrated mass in the night in a church in L'Aquila that was heavily damaged. A church bell rang out 309 times at 3:32 am (0132 GMT) -- the exact moment that the 6.3-magnitude earthquake struck.
"Everything has been delayed. And young people are leaving. Politicians keep bickering," Molinari told Catholic news site tempi.it, adding: "We would like to see something move so we can start again. The situation is still critical."
Italian Senate speaker Pietro Grasso on Saturday laid a wreath at a student dormitory that collapsed four years ago, killing eight people.
Territorial Cohesion Minister Fabrizio Barca, who has promised to speed up the reconstruction, said: "The state cannot not rebuild this city."
A court in L'Aquila last year sentenced six scientists and a government official to six years in jail for multiple manslaughter for failing to provide sufficient warning to local residents following a wave of small tremors.
The seven defendants are appealing the sentence.