The history of the Civic Library (Biblioteca Civica) in Koper has not as yet been studied in depth. The only considerable research about its history was done by Miroslav Pahor. His work is based on some archivial foundations but most of his views and interpretations are incorrect. This new essay is the result of the analysis of all the existing archivial data and presents new facts that replace the existing knowledge. The Civic Library in Koper was founded in 1850, almost 30 years earlier than we thought. The library took up residence in the Gymnasium. Some results of the study relate to the last period of activity of the Civic Library during and after the end of the Second World War. The Civic Library functioned until 1952, when the new Civic Library was founded. Therefore, for a short period of time two civic libraries in Koper actually coexisted.