The gallery was founded in 1972 under the name of Estiarte, although Pilar did not enter until five years later. In its beginnings, the gallery specialized in graphic work, including exhibitions of foreign artists of the highest level.
In 1991 Pilar took over the leadership, replacing Gonzalo Cabo, and began to accommodate a greater number of languages such as the work on paper or photography. Nevertheless, in the art world, Estiarte was still identified only with the graphic. For this reason, in 2010 he made the decision to change the name to his own. The Pilar Sierra Gallery was born. Two years later another great change took place, this time physical. The gallery moved from Calle Almagro number 44, where it had remained during the last four decades, to the street Santa Engracia number 6, place that occupies today.