The authors researched the incidence of suicidal thoughts and related factors in 123 patients of the psychiatric ward of the Hospital of České Budějovice with diagnosed attempted suicide in their medical history for the period from January 2013 – June 2015. The research was carried out in two stages. At the beginning of the hospitalization, quantitative data collection was implemented using a semi-structured questionnaire, followed by qualitative research conducted with semi-structured phone conversation, based on previous patient's written consent. The research data were statistically processed to obtain information about the character of relations among individual characteristics. To quantify them, the Bayesian Network (BN) was constructed, and to identify relations among individual characteristics, the Hill-Climbing algorithm was used. Before deriving the network, variables were discretized. The network parameters were set based on a data matrix using the maximal plausibility method. The results of analysed set show that the probability of suicidal thoughts is high, achieving a value of 0.750 (0.781 for women and 0.724 for men). If the patient visits a contact centre for drug-addicted persons, the probability of suicidal thoughts decreases to 0.683. If the patient visits a psychotherapist, the values of 0.736 are achieved. If a daily care centre is visited, the estimated risk rises to 0.832 and the probability of the patient repetitively attempting suicide is 0.606. If the interviewed person regularly consumes alcohol, the probable relapse amounts to 0.616. But if the person consumes alcohol from time to time, the probability rises to 0.701. In case of abstinence, the probable relapse decreases to 0.565. The incidence of suicidal thoughts in observed patients was high, and the amount of risk was influenced by gender, by visiting follow-up care facilities, psychotherapy, and particularly by the frequency of alcohol consumption. Intermittent alcohol consumption is the highest-risk factor in connection with relapsing suicide. In case of psychiatric patients with attempted suicide in their medical history, all verified preventive and therapeutic procedures that can contribute to prevention of relapses should be used within follow-up professional care. Specific approach of the closest social environment, medical literacy of the population and state safety measures are important.