Objective. In a cross-sectional study, we previously identified 2 potentially modifiable risk factors for adverse outcomes in systemic lupus erythematosus (SLE): self-efficacy and social support. The goal of this study was to evaluate in a randomized controlled trial a theory-based intervention to improve patient selfefficacy and partner support to manage SLE.Methods. Patients with SLE ages 18 years and older who met the American College of Rheumatology criteria and were able to identify a partner (spouse or family member) were recruited from 2 academic medical centers and randomized into an experimental group or a control group. Patients in the experimental group and their partners received an intervention designed to enhance self-efficacy, couples communication about lupus, social support, and problem solving, in the form of a 1-hour session with a nurse educator followed by monthly telephone counseling for 6 months. Patients in the control group and their partners received an attention placebo, including a 45-minute video presentation about lupus, and monthly telephone calls. Measures of physical and mental health status, disease activity, and psychosocial factors were collected at baseline, 6 months, and 12 months. The effect of the intervention on physical and mental health and disease activity at 6 and at 12 months was modeled with linear regression and adjusted for baseline health status, disease activity, sociodemographic factors, treatment change, and psychosocial factors.Results. One hundred twenty-two patients (plus their partners) were enrolled and randomized as follows: 64 to the experimental intervention and 58 to the attention control group. The participants were predominantly white, approximately half were college educated, and the groups were balanced for sociodemographic factors. At 6 months, significantly higher scores for couples communication (P ؍ 0.01) and problem-focused coping (P ؍ 0.03) were seen in the experimental group compared with the control group. At 12 months (6 months after the intervention ended), social support was higher (4.4 versus 4.1; P ؍ 0.03), self-efficacy was higher (7.2 versus 6.2; P ؍ 0.02), couples communication was higher (3.5 versus 3.1; P ؍ 0.03), and fatigue was lower (5.1 versus 6.3; P ؍ 0.02) in the experimental group compared with the control group. Global mental health status at 12 months, as measured by the Short Form 36 survey, was 69 points in the experimental group compared with 58 points in the control group (P ؍ 0.04). In multivariate models, adjusting for baseline covariates, scores for couple communication (P ؍ 0.01) were significantly higher at 6 months, and scores for self-efficacy (P ؍ 0.004) and global mental health status (P ؍ 0.03) were significantly higher at 12 months in the experimental group compared with the control group, and the mean score for global physical function was higher by 7 points, which was a clinically meaningful