The purpose of the present study is to point out suicidal contagion and suicidal collusion describing clinical cases, to improve professional skills in suicidal risk evaluation and management. In suicide contagion we described three typologies of contagion between therapist and patient: 1) suicide contagion of the environment on the therapist and on the patient; 2) suicide contagion of the therapist on the patient; 3) suicide contagion of the patient on the therapist. We described also four typologies of suicidal collusion with specific kind of patients: 1) with patient suffering of physical illness; 2) with patient suffering of a serious mental illness; 3) with manipulative patients; 4) with patient who is aggressive toward himself and toward other people. In conclusion we pointed out the importance of an adequate recognizement and management of suicidal contagion and collusion to decrease patient suicidal risk.