Small towns are an important element of settlement network. They change their status depending on, among others, the development of industry, and changes in the transportation system. Some of them lost civic rights, then regained them, and sometimes were incorporated into the neighboring agglomerations. Some small towns have merged together to create new structures in the settlement network. This article investigates this phenomenon on the example of south-west of Poland. It was also found that in several cases, a small town subsequently separated from the urban area and created a separate urban unit of its own.