X-ray techniques were used extensively in this work to examine ceramic samples. The well known techniques including : (1) identification of phases and chemical species, (2) peak separation, (3) quantitative phase analysis, (4) intensity band simulation, and (5) line shape analysis, were applied to ceramic materials of silicon nitride, zirconia toughened alumina, fully and partially stabilized zirconia. A theoretical derivation of the x-ray intensity from a rough sample based on a statistical roughness model was carried out. The statistical model was then combined with the intensity band simulation technique to simulate the intensity band from a rough sample. The modified technique for intensity band simulation was used to determine the strain profile in the near surface regions of a flat and a rough fully stabilized zirconia samples. The results show that a compressive zone is present in the near surface region of each sample. A partially stabilized zirconia disk was examined using symmetrical and asymmetrical diffraction optics after a prolonged pin on disk wear test. The different diffraction optics provided different probe depths and revealed a depth gradient of the phase distribution. A general picture of the wearing process of ceramic components is described based on the examinations carried out in this work.Ph. D.