Although recognized primarily for his orchestral music, like most composers of his day Rosetti also wrote music for the church. Intended as a youth for the priesthood, he was introduced early in his life to the role of music in the liturgy of the Roman Catholic Church. He then spent sixteen years at Wallerstein in the service of a Catholic family. With his move to northern Germany in 1789, Rosetti found himself at a Protestant court. While, during his last years, Rosetti composed several works that reflected the religious traditions of his new surroundings, it was the Catholic Church for which Rosetti intended the majority of his sacred music. Masses and Requiems account for the bulk of this repertory, which also includes hymns, cantatas, and settings of other texts such as Miserere mei and Salve Regina. The majority of this music is for soloists, chorus, and orchestra, but there are also a few pieces for smaller groupings.

Problems of attribution, which plague any consideration of eighteenth-century music, are especially intense with this repertory. Several compositions are found in manuscript copies attributed to other composers, and there has been some confusion between different musicians with the name Rosetti or Rosler. The general lack of certainty surrounding the sources of Rosetti's church music makes it impossible to ascertain with absolute confidence the authenticity of individual works. This limitation in turn seriously diminishes our ability to assess his stylistic development.