The Flag consists of two horizontal halves: the upper red and the lower blue. Between the stripes the Sun of May appears surrounded by 40 white stars.
The flag was created by the artist Claudio Trinajtich, winner of a contest that arose from the initiative of Mayor Oscar Sánchez Fabre. It was made official on September 20, 1999, according to Resolution 2,803 / 99 of the Departmental Board of San José.
The colors correspond to those of the Artigas Flag, also present on the Department's shield. The blue symbolizes the Republic, while the red represents the blood shed in defense of freedom. The Sun of May is "the one that gives life". The forty stars represent the 40 families from the Maragatería (Spain), founders of the departmental capital. The flag format is 2: 3, and it is found in all government buildings in the Department.