One of the global environmental problems which threaten the earth and humanity is the Ozone Layer Depletion and the negative results that it causes. With this study, the aim is to determinate the knowledge level of pre-service elementary science teachers about the causes of the Ozone Layer Depletion, results and the precautions they will take. In this study, 30-item-questionaire has been applied to 319 pre-service elementary science teachers using survey model. Percentage (%), frequency (f) and the singlefactor variance analysis have been applied to the data obtained from application using this SPSS statistical packet program. At the end of the analysis, it has been revealed that pre-service teachers who educate the generations that will face up with this important environmental problem have both some misconceptions and inadequate and locking knowledge about Ozone Layer Depletion. Besides, it has been determinate that specific there is no difference between knowledge level of pre-service elementary science teachers about Ozone Layer according to grade level.