Under Italian law, records of births, marriage, and death are maintained by the Registrar of Vital Statistics (Ufficio Anagrafe e Stato Civile) in the municipality (comune or municipio) where the event occurred.
In Italy, unlike other countries, there is no regional, or provincial office that maintain the above records records for more than one municipality.
When applying for one of those certificates, the applicant is supposed to supply all relevant information to the municipality which performs the research. Generally, the city registrar or city clerk unable (or unwilling) to perform extensive research to locate a record which is not clearly identified, and in most cases will not accept requests in a foreign language. Therefore, all requests should be written in Italian.
Italian registrars are not required by law to assist in genealogical research work. In most places, records dating back as far as the mid-19th century are available but unless complete and correct information is provided, no search is performed. If you are engaged in family tree reconstruction and do not have the essential information pertaining to your ancestors, you may wish to retain the aid of a firm specializing in genealogical work.
See below for request forms templates that you can use to request a vital record certificate in Italy:
BIRTH CERTIFICATE REQUEST: fill out the following form Certificato di Nascita(PDF, 93kb)
MARRIAGE CERTIFICATE REQUEST: fill out the following form Certificato di Matrimonio (PDF, 51kb)
DEATH CERTIFICATE REQUEST: fill out the following form Certificato di Morte (PDF, 48kb)