Beppe first appears when George Palmer and Peggy Mitchell attend his father's funeral in January 1998. He moves to Albert Square in February 1998, with the rest of his family: mother Rosa, brother Gianni and sisters Teresa and Nicky di Marco. Beppe's family come to Walford to open an Italian restaurant, while he has built himself a successful career in the police force, progressing through the ranks to the Vice squad.
Upon his arrival, Beppe instantly clashes with the Mitchell brothers, Phil and Grant Mitchell, who are known to dabble on the wrong side of the law and Beppe sees them as trouble makers. Beppe's animosity towards Grant, in particular, increases when he forms a close friendship with Grant's abused wife Tiffany Mitchell. It isn't long before Beppe falls in love with Tiffany and urges her to leave Grant for him. Beppe confronts Grant in The Queen Victoria public house over his cruelty towards Tiffany and the pair brawl. Tiffany decides to leave Grant after she finds him in bed with her mother Louise Mitchell and she packs her bags ready to flee Walford with her and Grant's daughter, Courtney.
However, just as Tiffany is about to leave, she falls down the stairs, leading everyone to suspect that Grant had pushed her. Beppe is furious and arrests Grant for attempted murder. He also coerces Tiffany, who is recovering in hospital, to pretend Grant had pushed her in order to keep him locked up. Tiffany does but her conscience gets the better of her and she later writes a letter exonerating her husband of any wrongdoing and instructs her best friend, Bianca Butcher, to hand it to the police after she has left Walford. However, before she leaves, she is killed in a car accident, whilst trying to reclaim her child from Grant, who has been released on bail the same day. Since Tiffany had been on the verge of eloping with Beppe, he never forgives Grant, and when he gets the letter that exonerates him, Beppe burns it rather than see his enemy cleared. Beppe is subsequently kicked off the force for withholding evidence and police misconduct. When Grant finds out about the letter, he punches Beppe.
Now out of work, Beppe gets a job as a cab driver working for Barry Evans and later embarks on a stormy relationship with Grant's little sister, Sam Mitchell. Sam takes the relationship more seriously than Beppe, and becomes extremely jealous of his platonic friendship with his flatmate Nina Harris, so their relationship doesn't last long.
In 2000, Beppe becomes a partner with Steve Owen and takes on management of his nightclub The E20. His police contacts come in handy soon after when drugs are found in the club and he manages to persuade them to turn a blind eye.
Also in 2000, Beppe's estranged wife Sandra arrives, hoping to gain access to their son, Joe. Although she is met with hostility at first, she and Beppe soon grow closer and eventually rekindle their romance, much to Beppe's family's disgust. Because of his ties, he also decides to stay in Walford when the rest of his family move to Leicester. Beppe is still in love with Sandra and soon begins pressurising her to have more children. The suggestion is met with hostility and she flatly refuses. Soon after, Beppe's old vice-squad partner, Jack Robbins, arrives in Albert Square looking for Sandra. It turns out that Sandra had been involved with Jack for years before returning to Walford. She had left him following a miscarriage that left her unable to have children. Sandra tries to deny her feelings for Jack, but eventually she admits that she is still in love with him and has only reconciled with Beppe so she can get custody of her son. She and Jack reignite their romance and Sandra makes plans to flee Walford with Jack and Joe. However, Beppe catches them just as they are about to leave and when he realises what is going on he attacks Jack, takes Joe back and denies Sandra any access. Sandra and Jack subsequently threaten to take Beppe to court for custody of Joe. Beppe retaliates by using his police contacts to plant drugs on Jack, getting him sacked from the force. The constant rowing is having a negative effect on Joe and he finds it difficult to choose between his warring parents. This culminates in him getting hit by a car when he disobeys his father and runs across the road to be with his mother. Joe is not seriously hurt, but the accident makes his parents rethink their behaviour. Beppe eventually allows Sandra visitation rights and so she leaves Walford with Jack the following year.
In 2001, before Steve is killed in a car accident, Beppe buys out his share and becomes sole owner of the club, which is a massive shock to Steve's wife Melanie Owen, as she has been led to believe that she is the sole owner. During this period, Beppe spends much of his time having sex with anonymous women and dumping them when he gets bored. He even contracts a minor STD. Beppe becomes close to Lynne Slater, who regularly babysits Joe whilst he is working, and she helps point out the error of his womanising ways. Beppe falls for Lynne and attempts to stop her marrying Garry Hobbs, but although Lynne is tempted, she goes ahead with the marriage.
In 2002, Beppe gets news that his mother has died of a heart attack, which prompts him to sell his club to Sharon Watts and leaves Walford to tend to his grieving family.