The objective of this study was to analyze the prognosis and predictors for patients with spontaneous isolated superior mesenteric artery (SMA) dissection (SISMAD). A total of 147 consecutive SISMAD patients from 2013 to 2017 were evaluated retrospectively. Forty-eight clinical, radiologic, and laboratory prognostic factors were counted and evaluated using univariate and multivariate logistic regression analyses. The follow-up time was 6 to 66 months (average, 31 months). Complete remodeling was observed in 32 patients (22%). The independent predictors were heart rate (hazard ratio [HR], 0.358; P = .031), alcoholism (HR, 0.272; P = .023), SMA normal diameter (HR, 2.674; P = .047), and SMA thrombosis (HR, 0.186; P = .009). Thirty-eight patients (26%) still had clinical symptoms, and body mass index (HR, 2.735; P = .036), initial symptoms (HR, 2.534; P = .045), and aorta-SMA angle (HR, 0.418; P = .049) were demonstrated to be significant predictors. The radiologic and clinical prognoses were inconsistent in 89 patients and associated with initial symptoms (HR, 0.288; P = .004) and SMA normal diameter (HR, 2.894; P = .016). The overall prognosis of SISMAD was fine. However, the rates of complete remodeling and complete recovery of symptoms were relatively low, and the radiologic and clinical prognoses were inconsistent.