A geophysical survey on the site of the former Cistercian abbey in Tennenbach, a subarea of the German town of Emmendingen, became necessary due to planned roadwork. While information is readily available on the abbey's demesne and wealth, prior to this geophysical prospection, there has been almost no indication of the extent and layout of the medieval buildings of the abbey, which was founded in the 12th century. Geomagnetic mapping enabled us to narrow down the area of the actual abbey itself and record the position of individual structures. These measurements were disrupted by a number of intense anomalies that could be traced back to several modern supply lines, so the 5-hectare site was resurveyed once more using ground-penetrating radar (GPR). The GPR method enabled the production of a detailed layout plan of the abbey. Besides identifying column bases of the abbey's church, it was also possible to record individual rooms of the outbuildings and two cloisters and to recognize the foundations of buildings from the earliest phases, which lie even deeper in the ground.