BACKGROUND: In practice psychiatrists rely on their own experience and intuition to evaluate the suicide potential of individual patients, but the algorithms for the decision-making process remain unclear. OBJECTIVES: (1) to establish models for the decision making process for evaluating suicide risk; (2) to simulate the impact of information concerning the number of previous suicide attempts on the clinician's ability to detect patients who performed medically serious suicide attempts (MSSAs). METHODS: Four decision models (linear, dichotomized, hyperbolic, and undifferentiated) depicting the influence of the number of previous suicide attempts on the clinician's recognition of MSSAs in 250 psychiatric inpatients were elicited and tested by a series of discriminant analyses. RESULTS: The dichotomized model ("all or none") was found to be the most efficient in detecting medically serious suicide attempts. CONCLUSION: The "all or none" paradigm seems to be the most appropriate way to evaluate the weight of previous suicide attempts in the decision-making process identifying medically serious suicide attempt patients.