In around half of cases, cheating partners are found out through indiscreet mobile phone text messages, emails betray one in five and a further one in 10 are given away by anonymous letters, according to the survey.
Seven in 10 affairs are one-off flings, with the rest more long-term relationships, it found.Infidelity is most prevalent in Milan, with Rome a close second, says the poll by the Italian Association for Family Lawyers.
Interestingly, the number of "serial adulterers" was increasing thanks to social networking websites which provide online space for married people, British newspaper 'The Daily Telegraph' reported.
Until 1981, Italian law recognised the principle of honour killings, with courts entitled to hand out more lenient sentences to men convicted of murdering their cheating wives. Nowadays, around half of cases of infidelity are tolerated by long-suffering partners, the survey found.