The question whether malarias of animals could be considered true zoonoses was examined. The research in this connection for the past decade or so was reviewed. That simian malarias are true zoonoses has been adequately demonstrated. In addition, there is great potential for human malarias being true anthroponoses. The author considers, therefore, that the significance of non-human reservoirs of human malaria in the control or eradication of malaria should be reconsidered.