Between April and July 1994, genocide was perpetrated in Rwanda during which more than one million and seventy four thousand (1,074,000) Tutsi were killed. This was a genocide planned and executed by the national authorities; it was also a mass genocide and genocide of proximity. The psycho-traumatic consequences in the population of Tutsi survivors were assessed through a longitudinal study conducted on genocide survivors seeking services at the Psychosocial Consultations Centre based in Kigali, Rwanda, during the period between 2000 and 2008. The research focused on assessment of the evolution of post traumatic stress disorder (PTSD) they were suffering from by reviewing medical records of 55 patients, using the international classification of mental diseases and also interviewing patients as well as clinicians. The study findings reveal that a high intensity traumatic event and the low income level of the family are causes of therapeutic failures. Specifically, dissociative aspects of PTSD experienced by victims of sexual rape are indeed a big challenge to the establishment of a therapeutic relationship. It was also observed that traumatic reactivations for some patients caused chronicity or intermittent apparition of psychopathologic manifestations. Another phenomenon observed concerns the somatic diseases concomitant to PTSD. Indeed, we had patients for whom somatic problems obstructed the manifestations of PTSD, hence delaying their treatment. Finally, a phenomenon of aggravation of PTSD by acute depressive disorders for almost all patients was additionally observed. Overall, the experience of the trauma of the survivors of the Genocide of the Tutsi of Rwanda leads the researcher to the recognition of multiple evolutions. It has been possible to observe a benign evolution and also a remission punctuated by periods of relapses and, finally, an evolution towards severity.Mental health in the context of post mass violence is a major clinical reality. On the one hand, we have plenty of mental health illnesses in a strict sense of the word: chronic evolution PTSD, severe depression, psychosis, etc. Those situations often need an individualized medicopsychological approach, that is, basic mental healthcare. On the other hand, all that which genocide causes such as psychological suffering, sadness and emotional distress in people and communities requires group therapy approaches as well as socio-economic support. Person-centred group and community initiatives, delivered in cooperation with different sectors involved in management of those issues, are indicated.