BACKGROUND: Generally, families of critical care patients are not actively involved in the patients' care in meaningful ways. A family-centered care model formalizes each patient and the patient's family as the unit of care. Family-centered care comprises 3 concepts: respect, collaboration, and support. OBJECTIVE: To evaluate the effects on family-centered care of having critical care nurses partner with patients' families to provide fundamental care to patients. METHODS: At the control site, patients' families experienced usual care; at the intervention site, patients' families were invited to assist with some of their relative's fundamental care with nurses' support. The family-centered care survey was used to measure families' perceptions of respect, collaboration, support, and overall family care at baseline and 48 hours later. Multivariate logistic regression was used to determine independent predictors of scores. RESULTS: A total of 174 family members of patients participated (75 control, 99 intervention). Total median scores on the survey were 3.2 (control) and 3.2 (intervention) at baseline and 3.2 (control) and 3.5 (intervention) at follow-up. After adjustments in the multivariate model, the family-centered care intervention was the strongest predictor of scores at 48 hours (odds ratio [OR]=1.66; P<.001). Other independent predictors included relatives with previous critical care experience (OR=1.27; P=.006) and those who were partners of the patient (OR=1.33; P=.002). CONCLUSION: Partnering with patients' family members to provide fundamental care to the patients significantly improved the respect, collaboration, support, and overall scores on the family-centered care survey at 48 hours.