In 1456 Cassà de la Selva obtained permission to hold two annual fairs where merchants and farmers could meet to sell and exchange their goods. The festival of Santa Tecla, a saint invoked by the dying to have a sweet death, was chosen to mark the celebration of the lesser Town Fair (Festa Major) of Cassà or the autumn fair. In the early 20th century, the Fair of Santa Tecla had become an economic benchmark because important prizes were awarded to the best equine and bovine specimens and to the best and most numerous flocks of lambs, in addition to having a very notable recreational facet, featuring fireworks, sports and musical activities.

Today, the Fair has become Cassà's small festival, a very lively gathering in which different cultural and traditional events take place, plus parades, meetings of giant puppet or Gegants, embroiders, concerts... One of the main events held during the fair is the Nit del Cremat or Cremat Night, which takes place on Friday and consists of a dance of sardanas and in the interlude a flaming rum drink called cremat is served to all the residents and visitors.