Tonino Cianfarani, 41, was jailed on Monday for killing 35-year-old Samanta Fava in April 2012.
A search was launched after Fava was reported missing from Sora, a town south-east of Rome.
Police divers were brought in after Cianfarani claimed he had dumped her body in the Liri river after she died of an illness, Corriere della Sera reported last year.
But a police dog named Orso prompted investigators to break down a cellar wall in the home of Cianfarani’s parents in nearby Fontechiari, where they found Fava’s decomposing body, in June 2013.
Cianfarani was later arrested at Rome’s Ciampino airport as he returned from a trip to Sardinia.
He denied the charges against him and in court claimed Fava died by accidentally falling down the stairs, Corriere reported this week.
The number of women murdered in Italy has risen, with one victim every two days in 2013. Almost two thirds of the women murdered last year were killed by their partner or ex, research organization Eures said in a report published last week.