This study examines the variability and stability of coping in cancer subjects over time and situation. In a prospective longitudinal design 74 breastcancer patients have been followed for 3-5 yr at 3-6 monthly intervals. A variety of measures related to coping and adjustment were taken. This report limits itself to the findings of an instrument developed for this study, the Bernese Coping Modes in which 26 coping modes were rated by observers. Results confirm arguments in favour of both variability and stability in coping activity over time and situation. Two measures support stability: rank values and a multivariate measure (MDS) with three constant dimensions: (1) support and acceptance; (2) denial; (3) diversion by thought and action. Evidence for variability is: the potential range of coping modes and a large variety of additional modes at most observation times. Subsequently time measures of coping were attributed to eight predefined illness stages as distinct clinical situations. Thus variability or richeness of coping further increased. The implications of these findings for measurement in coping research are discussed.