The striker spent just one season at the Ramon Sanchez Pizjuan where he played just 15 times, scoring four goals.
Immobile then spent the second half of last season on loan at former club Torino, where he scored five goals in 14 appearances for the Serie A side.
The 26-year-old also has 15 caps for Italy and has scored one international goal.
.@ciroimmobile è un calciatore biancoceleste https://t.co/9HV3EQiQzR pic.twitter.com/fEUfDwE0d5
— SS Lazio (@OfficialSSLazio) July 27, 2016