Fungal pathogens of plants or animals invade their hosts either by secretion of lytic enzymes, exerting force, or by a combination of both. Although many fungi are thought to rely mostly on lysis of the host tissue, some plant pathogenic fungi differentiate complex infection cells that develop enormous turgor pressure, which in turn is translated into force used for invasion. In order to understand mechanisms of fungal infection in detail, methods have been developed that indirectly or directly measure turgor pressure and force. In this article, these methods are described and critically discussed, and their importance in analysis of fungal infection are outlined.