The process of stem cell transplantation (SCT) is both intra and inter dependent; like patients, spousal caregivers (CGs) are affected by the experience. Few empirical investigations have focused on the needs of CGs or dyadic differences over the course of adaptation—the foci of the present study. SCT recipients and spousal CGs (n=131 dyads) completed the Profile of Mood States (POMS) and the Dyadic Adjustment Scale at three time points: pre-transplant, 6 months post-transplant and 1 year post-transplant. A separate, non-medical group completed the POMS as a normative sample. CGs reported higher levels of depression and anxiety as compared to patients and non-medical norms. With respect to marital satisfaction, couples were matched in their perceptions of the relationship prior to transplantation but grew mismatched over time. Six months and 1 year post-transplant, CGs reported lower levels of marital satisfaction relative to their patient counterparts. Counter to prediction, change in CG marital satisfaction (from pre-transplant to 1 year post-transplant) was predicted only by CG gender, not patient physical, nor psychosocial characteristics. Findings offer implications for person-specific and relationship-protective interventions. Copyright © 2002 John Wiley & Sons, Ltd.