Voltage sag is the most common power quality problem, which has significant consequences for industrial customers. In industrial facilities, microprocessors and semiconductor-based automated equipment is widely used. These devices are extremely vulnerable to deviations in supply voltage. Consequently, the voltage sag performance of industrial facilities needs to be assessed by measurement studies to determine root causes, characteristics and the size of the problem. In consultation with AF Consult Turkey, Trakya Electricity Distribution Company conducted an R&D project funded by the Turkish Energy Market Regulatory Authority to characterize and analyze voltage sag events in electrical distribution networks. In this study, power quality measurement with an IEC 61000-4-30 Class A monitoring device was performed in a textile facility in the Thrace region. The event records were evaluated using sag indices according to IEEE Std. 1564-2014 and voltage waveforms were analyzed. Furthermore, the root causes, the cost of voltage sag events and possible mitigation methods were explored.