A single-nave church with a rectangular nave of four bays, with a tower in the façade, with a monastery adjoining to the west. The soaring tower, decorated with coats of arms, is topped by a tall cupola. In the niches of the façade are statues of the patron saints, St Catherine and St Stanislaus. The richly decorated nave, vaulted with a collector's vault, with regency ornamentation, shows a Marian programme. The church was built immediately after Stanislaus Leszczynski became Duke of Lorraine, on the site of a historically very important chapel of the same name, which had existed here since the end of the 15th century and was built to commemorate the victims of the Battle of Nancy in 1477 (and extended in the 17th century). This ducal foundation, with a statue of the Virgin Mary (Mansuy Gauvain, 1505) in the main altar, became a popular pilgrimage site. The original meaning of the church's invocation, Mary's 'good help' in the Lorraine victory over the Burgundians, extended to the miraculous action of the image and Marian care for the inhabitants of Nancy and the surrounding area. The popular cult of the miraculous Madonna was exploited by Stanislas Leszczynski, immediately after assuming the throne of Nancy, placing himself under the protection of Notre-Dame de Bon-Secours and deciding to build a new church. This was the first independent realisation of the architect Héré, who became Leszczyński's court builder and author of the main buildings in Nancy and the surrounding area. The dethroned king of Poland had decided to place his family mausoleum here (the Dukes of Lorraine had previously been laid to rest in the Cordeliers church in Nancy). The simple massing of the small church draws on local tradition, while in the detailing Héré drew on the inspiration of his master, Germain Boffrand, and even specific solutions for the façade of the nearby Malgrange palace. However, associations with Central European Baroque, which were alien to French architecture, were also pointed out. "An interesting aspect of the architecture of Notre Dame de Bonsecours is the Gothic motifs: the unusually slender proportions, the trilateral closure of the chancel and the scarps" (Jan Ostrowski, p. 105). Plans of the church were published in 1752 in Héré's 'Recueil des plans... Héré'.

A few years after its construction, the church indeed became the family mausoleum: in 1747 Catherine Opalinski, wife of Stanislaus, was buried there. The founder himself was laid to rest in the local crypt in 1766. The tombstones of both were made by the eminent French sculptors Nicolas-Sebastien Adam and Louis-Claude Vassé. In 1768, the heart of the daughter of the founding couple, Queen Marie Leszczynska of France, was laid to rest in the church. Members of the Ossolinsky family, cousins of the king, are also buried there. These tombs were profaned during the French Revolution, and the church was significantly devastated in the process. After 1806, the damage was repaired and the tombstones, rescued from the local museum, were restored. However, they were reassembled in a manner inconsistent with their original state. The church has served as a parish church since 1844.