Their rule, based on the rule of St. Augustine, received papal approbation in 1859, and additional constitutions were confirmed by Leo XIII in 1892. Their work includes the direction of all manner of charitable institutions, such as domestic and trade schools, homes for first communicants, protectories, poor-houses, homes for defectives and female reformatories, as well as the care of the sick in their homes. They also have charge of schools, including a number of normal institutes in Austria. Candidates must spend one year as postulants and from three to four and a half years as novices before being admitted to the congregation. The auxiliary sisters for the care of the sick renew their vows annually.
There are several entirely independent branches of Borromean Sisters. In 1838 one was established by Aloysius Joseph Freiherr von Schrenk, Prince-Bishop of Prague (died 1849), which was confirmed as a separate congregation in 1841, and in the early 20th century had 900 members in 102 houses, chiefly in Bohemia, Moravia, Upper Austria and Lower Austria. In 1848 Melchior Freiherr von Diepenbrock, Prince-Bishop of Breslau, invited the Prague Borromeans to found a house at Neisse, which, in 1857, was raised to the rank of the mother-house of a separate congregation. Later the mother-house was transferred to Trebnitz, and temporarily, during the Kulturkampf, to Teschen, where a provincial house for imperial Austria was later established (1889). A house of this congregation founded at Alexandria in 1884 was, in 1894, made a provincial mother-house and a novitiate for the (Ottoman) Orient, with the direction of schools, an asylum for the aged, and a hospice for German pilgrims. Affiliated foundations have been made at Jerusalem (1886), Haifa (1888), Cairo (1904) and Emmaus. The members of the Trebnitz congregation numbered 1900, in 211 houses circa 1910. In 1811 a foundation was made from Nancy at Trier whence the congregation spread to other cities of Western Germany. In 1849 a provincial house was erected at Trier which by decree of Pius IX (18 September, 1872), was made the mother-house of an independent congregation. A famous Borromean institution is St. Hedwig's Hospital at Berlin, founded in 1846 by Angelika Eschweiler. The Trier branch comprises over 1200 sisters in 70 houses. A foundation was also made at Maastricht (Dutch province of Limburg) in 1837 by Peter Anton van Baer.