The issue of sonic heritage in sacred historic buildings is gaining popularity and becoming a frequent subject of discussions. The Baroque St Joseph Church of Carmelite Fathers, a minor basilica, is, architecturally and culturally, an exceptional place in Poznań, a city located in western Poland. The church is often used as a concert venue. It underwent an acoustic study with the use of a sound source situated in the presbytery and on the pulpit. The aim of this paper is to present results of acoustic investigations and to compare its acoustic properties with other churches. Acoustic parameters acknowledged as primary values used to assess acoustic properties of a religious building were investigated and then compared with recommended values. Placement of the source in two measurement points rendered it possible to carry out speech intelligibility analyses for a variable position of the sound source, and, in effect, enabled functional assessment of the historic pulpit. Thus obtained results were compared with European Baroque churches whose parameters are available in the literature.