PURPOSE/OBJECTIVES: To assess the degree to which postsurgical adjustment in patients with breast cancer and their partners depends on the nature of the patient-partner dyad relationship. DESIGN: Secondary data analysis from a randomized controlled trial. SETTING: Three cancer centers and one suburban community hospital in New York. SAMPLE: 205 patient-partner dyads (112 intimate-partner, 58 family-member, and 35 nonfamily-member dyads). METHODS: Mann-Whitney nonparametric comparisons and chi-square tests were used to assess dyad types on continuous and categorical variables, and a mixed model for repeated measures compared postsurgical adjustment among dyad types. MAIN RESEARCH VARIABLES: Type of patient-partner dyads and physical, emotional, and social adjustment. FINDINGS: Patients in intimate-partner dyads were younger, had greater incomes, and discovered the lump by routine mammogram as compared to family- or nonfamily-member dyads. No significant differences were observed in patients' physical or emotional adjustment. Patients with intimate partners had greater difficulty in their social and domestic environments. Partners in intimate-partner dyads had lower scores on psychological well-being, more problems in social and domestic adjustment, and less social support to promote social adjustment. CONCLUSIONS: Women with breast cancer experience successful physical and emotional adjustment whether they have intimate-partner, family-member, or nonfamily-member partners. Intimate partners are at greater risk for emotional and social adjustment issues. IMPLICATIONS FOR NURSING: When designing interventions, consideration must be given to the type of patient-partner dyad involved.