This study assesses the environmental proficiency of Texas life science educators certified from 2003 to 2011 by analyzing their TExES 138 8-12 exam results in domains V and VI. The sample consisted of all the individuals that took and passed the TExES 138 life science 8-12 exam. During this period, approximately 41% of the individuals who took the exam actually passed it. This study employed non-experimental, quantitative statistical methods to evaluate educators that passed the exam for proficiency in environmental science content knowledge and how to teach and assess science learning. Because this study focuses on improving environmental science literacy, the TExES 138 exam was selected. This exam contained a domain dedicated solely to environmental science and comprised a larger portion of the exam than other certification tests. Data were provided by the Texas Education Agency in response to an open records request. The variables of interest were year, total test score and scores in domains V and VI. Data were analyzed using t-tests. Analysis of data revealed a significant difference in educator proficiency in environmental science content knowledge and how to teach and assess science learning at the 95% confidence level. Mean scores for the individuals that passed the exam are significantly different from mean scores in domains V and VI. The educators certified from 2003-2011 demonstrated weaknesses in the environmental science content and the content of how to teach and assess science learning. Educators certified during this time period may struggle with teaching environmental science and assessing student learning in science. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]