Abstract: Several medical conditions (diabetes, cardiovascular diseases, hypercholesterolemia, etc) or modifiable behavioral habits (smoking habit and alcohol assumption) capable of causing damage to the peripheral microcirculation are considered potential risk factors for degeneration/tear of the rotator cuff. The aim of the study was to analyze and quantify how the association of multiple known risk factors is more effective than the predisposing action of a single factor. Three hundred eight consecutive patients who underwent arthroscopic repair of a full-thickness rotator cuff tear (RCT) represented the case group. The control group included 388 consecutive healthy asymptomatic subjects for shoulder pathologies. A multivariable prognostic model for the prediction of RCT has been performed to analyze the mutual effect of multiple risk factors. With a correct classification estimated at 70.6%, a smoker patient [odds ratio (OR) = 2.405; 95% CI = 1.645-3.516] with hypercholesterolemia (OR = 1.976; 95% CI = 1.408-2.771), diabetes (OR = 2.362; 95% CI = 1.241-4.493), and arterial hypertension (OR = 1.630; 95% CI = 1.156-2.300) has a higher chance of developing a RCT surgery compared with a peer nonsmoker healthy subject. The probability of a smoker patient suffering from hypercholesterolemia, diabetes, and arterial hypertension undergoing rotator cuff repair surgery is not given by the sum of the probabilities of each condition but increases dramatically. Each pathology interacts with each other; dramatically increasing the risk of developing a cuff tear. Level of Evidence: Level III—retrospective study.