Undercover cop Nico Giraldi travels to New York and Las Vegas to find a crooked cop who gave his squadron back in Italy a bad name.

Now an agent of Interpol undercover, the former Inspector Giraldi, goes to New York to find his friend Salvatore Esposito, aspiring restaurateur in Little Italy, suffocated by debts with the usurers headed by Don Gerolamo. He will remove the gang and assure her of justice, but she will suffer the advances of the Boss's daughter, the ugly Maria Sole.

In The Cop in Blue Jeans, a fearless undercover cop named Nico Giraldi must go deep undercover to infiltrate a criminal organization and put an end to their evil schemes. Along the way, he encounters various obstacles and dangerous situations, ultimately leading to a thrilling climax.

The officer Nico Giraldi investigates a homicide which has taken place in a Chinese restaurant in Rome. His wife and his son are kidnappeded by the murderer in the course of the inquiry. In the end the case is worked out.

A rude Roman policeman Nico Giraldi and an English detective team up in search of a gang that has carried out an enormous fraud against the Lloyd's of London.

A gang of thieves are robbing luxury apartments in Rome, but after emptying the villa of the wealthy Mr. Douglas, the thieves are beginning to die.

Rome, Italy, early 1980s. A guy who worked at the Blue Gay, a transvestite cabaret, is found murdered, strangled. Marshal Nico Giraldi is responsible for investigating, infiltrating the Roman Gay community.

Undercover cop Nico Giraldi is once again transformed, now as a trucker in a criminal gang.

A police inspector is called to Milan to investigate a murder case since he grew up in the same ghetto as the suspect.

A black-out occurs during the meeting of a gang of criminals. When the light is back one of them is found killed with a stab on his back and all the clues point to a penniless man who had an argument with the victim a short time before the murder.

While keeping an eye on his small time crook brother in law, Inspector Nico Giraldi gets involved in a murder case set in the world of Formula One racing. Giraldi is suspended for trying to cover up for his brother in law and becomes afraid his wife and son may be targeted next. Therefore he calls in the help of his childhood friend and chief informant, Venticello.