This descriptive-correlational investigation aimed at determining whether the environmental conservation knowledge of secondary teachers and students in private schools in the Division of Iloilo City will translate into conservation practices. It also aimed at ascertaining the significant differences and association between the environmental conservation knowledge and practices of teachers and the students. The dependent variable in this research was environmental conservation practices and the independent variable was the environmental conservation knowledge of teachers and students. Data needed for the investigation were gathered through the use of two pilot-tested instruments. Convenient sampling method was employed in determining the number of schools in Iloilo City. The questionnaire was administered to all science teachers and 221 proportionately and randomly selected senior students from seven selected private schools during the school year 1999-2000. The table of Krejcie and Morgan (in Michael and Isaac, 1990) was employed in determining the sample size of the given population. Descriptive statistics employed in the study were means and standard deviations. Inferential statistics were the t-test, and Pearson Product Moment Correlation set at .05 alpha level for two-tailed tests. Results of the study revealed that the teachers were very knowledgeable in environmental conservation concepts. The selected senior students were found to be knowledgeable of environmental conservation. In terms of environmental conservation practices, teachers and students obtained similar results of "rarely practiced". There were significant differences in the environmental conservation knowledge of teachers and students, but no significant differences were found in the environmental conservation practices of teachers and students. Moreover, no significant correlation existed between the teachers' environmental conservation knowledge and their conservation practices. Significant correlation existed between the students' environmental conservation knowledge and their conservation practices.