The importance of terminological systems (TS) to support standardized and structured documentation of medical data is commonly recognized. The usability of TS in real practice strongly depends on the completeness and the correctness of the content of the TS. We here present four different methods that can be applied to evaluate a TS' content. All four methods were applied in a case study. We make a comparison of 1) the results of two methods that focus on the completeness of the content and that differ in the application of the TS that they focus on and 2) the results of an automated and a manual evaluation of the correctness of the content. Finally we summarize the results of all four methods and analyze whether they overlap or complement each other.