This study determined the knowledge of the preventive strategies of Onchocerciasis among the Inhabitants of Riverine Areas in Southeast Nigeria. The study was guided by eight research questions and six null hypotheses. Descriptive survey design was used and the population of the study consisted of 4,177,828 of inhabitants in Anambra State and 3,927,563 of inhabitants of riverine areas in Imo State. The sample consisted of 1,200 inhabitants of the riverine areas in Anambra and Imo state selected using multi-stage procedure. The instruments for data collection Knowledge of the Preventive Strategies for Oncherciasis (KOPSO) It gave a reliability coefficient of 0.88 for section B and section C gave a coefficient of internal consistency of 0.90. Research questions were answered using Aggregate scores. frequencies and percentages were used to answer research questions, Chi-Square, statistics were used to test the hypotheses. The results showed that majority of the in Anambra and Imo states riverine inhabitants have knowledge of the preventive strategies of Onchocerciasis. There were significant differences in the knowledge of the preventive strategies of Onchocerciasis based on their educational Level, occupation and age except for their based on age, which has no significant different in the riverine inhabitants in their knowledge of Onchocerciasis. The following recommendations were made among others: There should be Community-based Campaigns on the knowledge and preventive strategies of Onchocerciasis for the Inhabitants of Riverine areas.