BACKGROUND Dentistry needs an accurate means of recording occlusal contacts. The authors undertook a study to evaluate the accuracy of occlusal contact marking indicators and the reproducibility of their results. METHODS The authors recorded occlusal contact areas using occlusal indicators made of paper, film and silk. They studied 10 indicators by testing them on articulator-mounted, impact-resistant casts and measuring the surface area of the resultant contact marks made on impact using a video camera, a frame grabber and a computer-linked image analyzer. RESULTS All indicators differed in surface area markings between and within groups. The indicator's thickness and color and the material from which it was made separately and interactively had an effect on the size of the markings. Measurements were evaluated at a P = .05 significance level. The authors used Bonferroni-adjusted cutoffs when computing post hoc pairwise comparisons. The data were grouped into four categories: descriptive statistics, comparison of indicators by surface area marked, indicator thickness and repeatability. CONCLUSIONS Indicators vary, and their markings may not be repeatable even when they are used alike. Further study is required, as is the development of an indicator measuring standard. CONCLUSIONS Indicators are used to determine occlusal disharmony and to establish occlusal harmony. Since the accuracy of the markings can be questioned, the interpretation of the markings may be correct but the accuracy of the markings themselves may be misleading.