The possible influence of spousal support on patient characteristics is examined within a longitudinal research design to assess coping and adjustment of 108 pa- tients after tumor surgery. Spouses are regarded as key sources within the patients' support networks. Their extension of emotional, instrumental, and informational support may improve coping attempts, such as accommodation, downward com- parison, fighting spirit, or search for meaning. The analysis was performed in a time-lagged fashion, with spousal support reported 1 month after surgery and pa- tient variables reported 6 months after surgery. Received support and coping were associated with earlier spousal support, but this partner effect emerged only for the subsample of dyads with female patients and male partners. Results are discussed with respect to gender differences and recent advances in the field of dyadic coping. In the context of dyadic coping with a critical life event, the present study mainly addresses three questions: (a) Can cancer patients' received social support be predicted by provided support, as reported by their spouses five months earlier? (b) Can cancer patients' coping be predicted by pro- vided support, as reported by their spouses five months earlier? (c) Are these relationships different for two subgroups of partner-patient