The present study used structural equation modeling to examine the relationships among disease stage (i.e. Stage II versus Stage IV), age, coping style, and psychological adjustment in 100 women diagnosed with breast cancer. Five separate models were examined: a full model, a mediational model, a demographic-disease model, a coping style model, and a regression model The analyses revealed that the present data best fit the mediational model in which age and stage of disease were not directly associated with psychological adjustment but, instead, were mediated by coping style (χ2(25)=45.776, AASR=0.05, CFI=0.94). The mediational model accounted for 56% of the variance in psychological adjustment. In particular, the model showed that younger women and women with an earlier disease stage used greater levels of the coping strategy characterized as a fighting spirit and lower levels of the coping strategies characterized as hopelessness/helplessness, anxious preoccupation, and fatalism which, in turn, were related to better psychological adjustment. Overall, these findings may offer an explanation for the conflicting findings regarding the relationship between age, stage of disease, and psychological adjustment to breast cancer by illustrating that coping strategies may be an essential mediating factor; in turn, a mediating model of psychological adaptation may offer useful information for clinicians as they implement interventions designed to improve patients coping efforts. © 1998 John Wiley & Sons, Ltd.