Due to the need of implementing effective methodologies for the training of citizens with environmental awareness, this research was posed with the aim of evaluating the effect of the interdisciplinary teaching in Environmental Education on environmental knowledge, values and attitudes of sixth grade students teaching of a public school from Los Angeles city, in Chile. Environmental Education is related to the subjects of Language-Communication and Mathematics. The measurement instruments were validated by a committee of experts and subjected to a reliability analysis. These instruments were applied before and after the intervention, allowing measuring the degree of change in environmental knowledge, values and attitudes in the different treatments which were statistically analysed by means of non-parametric tests. Results indicate that a higher degree of interdisciplinarity generates better knowledge, values and attitudes towards the environment. Hence, it is recommended to implement interdisciplinary strategies in the classroom at the time of performing Environmental Education.