The strength of concrete depends on various factors like type of cement, w/cm ratio, amount of cementitious material (cm), curing and environmental conditions, etc. However, the concrete structures weaken over time due to environmental factors such as chemical attacks, temperature variations, and other physical causes. If not addressed promptly, these issues can lead to rapid deterioration and cause the structure to fail to meet the functional requirements for its intended service life. Consequently, evaluating concrete quality is crucial for identifying potential weaknesses, assessing the overall health of the structure, and providing recommendations for maintenance and repair. The paper presents a case study that incorporates the application of several non-destructive testing (NDT) methods to evaluate the concrete quality of the Hirakud Dam, Odisha, which is approximately 75 years old. The NDT methods used in this case study include the ultrasonic pulse velocity (UPV) test, rebound hammer test, and cut and pull-out test. The ultrasonic pulse velocity test evaluates concrete quality, the rebound hammer test measures concrete uniformity, and the cut and pull-out (CAPO) test determines concrete’s in-place compressive strength. Additionally, this research paper focuses on the standard testing procedures for NDT, the sequence of operations required to ensure accuracy, and the issues encountered during testing. The results of this study are intended to enhance the understanding of the dam’s current state and to guide future efforts in preserving this critical infrastructure.