In 1980 he was arrested for participating in a betting scandal and banned from the Italian championship until 1982. In 1985, after Lazio had been demoted to the Serie B, he was ceded to Napoli for 5 billion lire.
Together with Careca and Diego Maradona, with whom he formed the "Ma-Gi-Ca" line, Giordano was instrumental in SSC Napoli's first scudetto of 1987. He later played for Bologna and Ascoli, before turning to a coaching career.
In the summer of 2006, Bruno Giordano was announced as the new coach of Messina, just relegated to Serie B. However, following the 2006 Serie A scandal, Messina was readmitted to Serie A, therefore allowing Giordano to finally coach a Serie A side. On 30 January 2007, following a series of poor results including a home loss to last-place Ascoli, Giordano was sacked, but then reappointed by Messina chairman Pietro Franza on April 2, following the firing of Giordano's replacement Alberto Cavasin. In his second tenure at Messina, Giordano lost all four matches before being sacked again on April 23, only 21 days after his reappointment. He was replaced by Bruno Bolchi.