Because of their versatility CrMn-stainless steels have become the most used structural materials in directional and while-drilling reservoir characterization tools. Nevertheless, pitting and environmentally assisted cracking (EAC) are a major concern when these materials are subjected to high halide-containing water-based drilling fluids at elevated temperatures. Consequently, pitting corrosion resistance becomes a crucial property to guarantee operational reliability and integrity of drilling equipment. Indeed, nickel-stabilized austenitic stainless steels and super austenitic stainless steels with higher contents of chromium and molybdenum have been recently developed as alternatives in drilling operations involving harsh environments. In this study, the pitting and repassivation behavior of several grades used in drilling technology was investigated using electrochemical methods. The tests were conducted in brines with different pH-values at temperatures ranging from ambient temperature to 150 °C. Experimental results are compared to PREN-Mod and CPT-values as well as to results from ASTM G48 Method A. The experimental data provided in this paper demonstrates the lack of correlation between the real pitting resistance of most grades commonly used in drilling equipment in brines at elevated temperatures and the commonly used PREN-Mod values. In addition, the limited applicability of results from standardized test methodologies for predicting pitting susceptibility in service is confirmed. The discussed electrochemical results provide on the other hand a more suitable basis for defining criteria regarding materials selection in drilling technology.