It is the second most important church in the city after La Seu Vella. The church of San Lorenzo is a Romanesque-style Catholic temple, but with Gothic extensions and finishes.

It has three naves of the same height, with three apses. The central nave, in Romanesque style, is the oldest. The other two naves are Gothic in style. Construction began at the end of the 12th century by the sculptors and craftsmen who worked with Pere de Coma, master builder of La Seu Vella. The side chapels and the octagonal bell tower - from the 15th century - are Gothic in style. The building conserves four important Gothic altarpieces, the largest dedicated to Saint Lawrence, that of Saint Ursula (attributed to Jaume Cascalls), that of Saint Peter and that of Saint Lucy. The coats of arms of Berenguer de Gallart are visible on the Gothic doorway of the Plaça de Sant Josep. The church, cathedral seat on two occasions, contains different pieces of art belonging to the Diocesan Museum of Lérida.

Of particular note is the sculpture of the Mother of God of the Apostles or Verge dels Fillols by the sculptor Bartomeu de Robió, from La Seu Vella, and a 15th century Gothic painting, Santa Maria de la Candelera, attributed to the painter Mateu Ferrer and depicting Saint Blaise. In 2002, the bell tower was restored to its former beauty thanks to the handcrafted reproduction of the coves of the railing and the original gargoyles.