St. Francis' Church is located in the homonymous square of Lucignano. The church, datable between the second half of the thirteenth century and the beginning of the Fourteenth Century, it has a single nave covered gabled, with transept slightly projecting and a polygonal apse, covered with a cross vault and flanked by two chapels. The facewalls bicromo of the facade is rather unusual in a Franciscan church. The apse is open by a mullioned window acute sixth of invoice similar to those of the sides.
There are many frescoes were discovered and restored. Among the most ancient one fourteenth-century depicting the Triumph of Death attributed to Bartolo di Fredi. In the left side of the transept is a large fresco of the sienese school with three scenes in three superimposed bands (St Francis receiving the stigmata, Madonna on the throne with saints Cristoforo and Giorgio, Epiphany).