Our objective is to identify in 137 true RAAAs operated consecutively in open surgery: (1) diagnostic therapeutic aspects capable of influencing results, (2) risk classes with different prognosis, (3) any situations where the prognosis is so negative that surgery is not recommended. The relationship of 16 anamnestic, clinical and technical parameters prospectively collected with 30-day mortality was retrospectively evaluated by uni- and multivariate analyses. Thirty-day mortality was 37%. The univariate analysis identified as mortality predictors Hb ≤ 8 g/dl and circulatory shock at hospitalisation, but following the multivariate analysis only circulatory shock was a certainly significant risk-factor. The cumulative effect on mortality of the two parameters identified at univariate analysis translates into a statistically significant difference in mortality between two groups of patients: A (no or just one risk-factor) and B (two risk-factors). To reinstate euvolemia, rather than adequate haemoglobin values, improves the chances of success. A simple prognostic index into two risk classes is feasible, but abstention from surgery is not justified in any type of patient.