Florencio Sánchez's parents moved him and his eleven siblings to the city of Treinta y Tres and later to Minas, where he attended elementary school.

At a very young age, he published a few satirical articles in a newspaper and participated as actor and author in some family musicals (with staged representations).

The critical and scathing realism was apparent in his literary work for the newspaper; this writing style would later characterize his theatrical productions.

In 1897, when the civil war broke out in Uruguay, he returned to his home country and fought under Aparicio Saravia, thus continuing his family's history of political action.

On August 13, 1903, his first play, M'hijo el dotor ("My son, the doctor"), was performed in the Comedy Theater of Buenos Aires.

In 1906, Sánchez settled in La Plata, where he worked for the Office of Anthropometric Identification, which was funded by Juan Vucetich.

In 1909, he found an opportunity to go and boarded the Italian ship Principe di Udine on September 25, arriving in Genova on October 13.

Upon receiving 3000 francs in 1910 for his play Los muertos ("The Dead"), he spent all of his money in just a few days in Niza on women and gambling in casinos.