Chile has become one of the last countries in the world to grant married couples the right to divorce.
The law which makes divorce legal was introduced in April but only comes into effect on Thursday.
The BBC's Chile correspondent says the law has overwhelming public support, and President Ricardo Lagos has described it as a major step forward.
But the Roman Catholic Church has warned it is a threat to the stability of marriage, and to the family.
The Church also argues that the separation periods before a divorce can be granted are too short.
Under the new law that overruns the 1884 marriage code, a couple may divorce a year after separating if both partners agree to split up. If one partner disagrees, a divorce is allowed after three years.
The BBC's Clinton Porteous in Santiago says the new law is expected to trigger a large number of applications in the next few months.
One woman planning to take advantage of the new law is 44-year-old Esther Sumastre. She is separated but still legally married, and believes divorce will liberate her.
"It's not for the money - it's to be free and to have the opportunity to start another life," she told the BBC.
Opinions polls have consistently shown overwhelming public support for divorce, even though more than 70% of Chileans call themselves Catholic.
Malta and the Philippines are the only countries that do not have a divorce law.