The study investigated the effect of rumours on the dissemination and utilisation of information for social stability in Plateau State concerning cattle rustling and alleged covert discrimination and accusation against Hausa/Fulani communities which no doubt created mistrust; enemity and disorientation among people in the state. The objectives of the study were achieved by formulation and answering sis (6) research questions and two(2) hypotheses tested at α level of 0.05. Some of the research questions sought to ascertain what are the causes of Rumour Mongering in Plateau State, what are the sources of social instability information in Plateau State, what types of social instability information disseminated in Plateau State, to what extent do rumour mongering affected the information disseminated in Plateau State. Survey research design was adopted for this research. Stratified random sampling and proportional allocation was used to obtain sample size of 301 from the population. The instruments used to collect data for the study were structured Likert-scale questionnaire and structured interview which were administered to community and youth leaders and individuals directly affected by crises in the flash points areas in communities in Barkin Ladi, Riyom, Jos north and Bassa LGAs. Data collected from the research questions were analysed using frequency count tables, histogram, bar charts, line graph and diagrams while Null hypotheses formulated were tested using Pearson Product Moment Correlation-PPMC and Chi-square. The research findings revealed amongst others that on the causes of the current social instability in Plateau, the state government failed to take holistic and proactive measures which should include quailing rumour dissemination and timely communication of strategic and tactical information to concern authorities in the state and at federal level for appropriate action. Misnomer or Name calling and refusal by some ethnic groups to allow inter marriage due to ethnic and religious lines brought in animosity among the people. Therefore, recommendations were made to include amongst others that there is need for the state government to take holistic and proactive measures that would include quailing rumour dissemination and timely communication of strategic and tactical information to concern authorities in the state and at federal level for appropriate action. Misnomer or Name calling should be reported to the police and inter marriage between and among ethnic groups should be encouraged and practiced.