The 52-year-old male nurse was caught trying to smuggle the drugs into a district prison in Taranto, south-west Italy, Ansa reported on Tuesday.
He had reportedly stuffed 28g of marijuana into a bottle of shower gel, but his plan was foiled by a sniffer dog at the prison.
News of his arrest came the same day 15 people in Padua, north-east Italy, were caught running a trafficking operation at a local prison.
Working with former prisoners and families of detainees, the group allegedly smuggled heroin and other drugs into the prison. Phones, SIM cards and USB sticks were sent into the prison, with the complicity of an officer from the prison police service, Rai News said.
Elsewhere in Europe, a female prison guard in Austria was suspended in May after smuggling a mobile phone into jail and falling pregnant to one of the jailbirds.