Press-processing of sheet molding compounds (SMC) is a highly productive technology for producing lightweight structures. SMC are mainly composed of a reactive resin material and unoriented fibers. The temperature-activated crosslinking reaction, also referred to as curing, transforms the liquid resin into a solid polymer that is capable of withstanding mechanical loads and protecting the fibers. The homogeneity of the curing reaction, however, remains a challenge that limits the productivity. To overcome this issue, sensor-based monitoring is a promising approach. While there is a large variety of sensors that can be used to detect the degree of cure (DOC), they are mostly limited to single or multi-point sensors. Hence, the detection of an inhomogeneous DOC distribution or local hot spots results in high costs. Over the past 20 years, numerous methodologies have been proposed for the monitoring of composite manufacturing processes that have employed electrical time-domain reflectometry (ETDR). However, the extant studies have focused on the flow front of the resin in infusion processes, as opposed to the curing of SMC, and have merely calculated a value for the DOC, averaged over the entire sample, from the ETDR data. In this contribution, a measurement setup is presented, allowing spatially resolved ETDR measurements during curing of an SMC. The results show local changes of the impedance along the sensor that can be correlated to the DOC. Two heating cycles are compared. While during the first cycle curing of the SMC takes place, the second cycle serves to detect the heating behavior of the cured part. By analyzing the differences between both cycles, values for the local DOC can be derived. To validate the suggested approach, differential scanning calorimetry (DSC) scans are performed. The results show that ETDR is a promising tool for in-situ process monitoring of thermoset based production technologies. It provides comprehensive data while being a cost-effective and flexible method.