She started her career as a professor of penal Law at the University of Genoa, then moved to the University of Parma.
From 1973 to 1975 she worked for Reformation Bureau of the Italian Justice Minister and represented Italy at Praga's 1983 World Peace Meeting.
She started to defend women from stalking and sexual violence and first in Italy during her work has used cruel words, during processes, to describe violence trying to shocking the italian society from the late 70's which always was reticent to women violence, to breaking silence among this stuff.
She took the defence of the survivor Donatella Colasanti, from the Massacre of Circeo (1975) where three guys invited two adolescents girls, known only same days before in a pub, to a party in ones of thier house at Circeo, near Rome. But no party was there, the two girls were tortured, violented and massacred for one day and one night. One of the slavedriver during the fact came back to Rome for not miss his family lunch, then came back to Circeo to continue the massacre: the two girls were druged, beaten and then, belived dead, putted in the three boys' car who went to Rome in a pub to drink something, but only one girl survived and from the luggage of the car could complain and so some citizens could call the police.
During the process, that shocked Italy for his violence due not only to misogen but also to social racism, the two girls in fact were from a media social class instead of the three boys who were from an aristocratic social class, Tina Lagostena could be able to defend the survivor girl Donatella saying she represented all women and Justice would be necesary not for revenge but for Justice itself.
She broke the cliché of women who cause the violence and that one which represent good girls staying at house, so bad girls are those who just want fun and friendship, for the first time she used the word "rape" in an italian Court.
At the end of the process she could reach to have a sentence of condemnation which transform italian value refered to women, thanks to her and her new woman style of making lawyer in a men's place as a Court.
With other women, engaged for women's rights, based, on 1988, the Pink Phone (Telefono Rosa) an association which gives free services to women in difficulty as legal support or psychological services or medical visits, this association remains the most important association in Italy for violented women also nowadays.
She has been the President of the National Gender Opportunities Commission of the Consiglio dei Ministri (the institution which coordinates the italian government) and member of the UE Gender Commission.
She was the italian Chief of the delegation at the Pechino's UN Conference for women's rights, on 1994.
She wrote also the important italian law for the sexual violence against women of the 1996 which for the first time established the civil principle that sexual abuse is a crime against a person and no more against public moral as first 1996 again in Italy was.
In 2003 she was one of the promoter for the change of the italian constitutional article number 51 which now establishes the equality for men and women in society with equal opportunities for both sex in public and private market.
From her book named "The lawyer of women" , on 1997, the public italian television made a tv-movie with the same title and starring by the most important italian actress.
In this video we see Tina during a process, of the '70s, defending a girl named Fiorella raped by four men, she knew, and who were told guilty by the Italian law even if in a derisory way!.