Abstract: The subject of this research is the peculiarities of organization of educational environmental geocaching for the public school students. Current a relevant trend in development of modern education is the model of open, informal education. Educational geocaching is one of the forms of organization of work with the students of informal education. Special attention is given to achievement of goals of environmental education using the activity approach. The authors believe that the students’ knowledge of environmental situation should be obtained through their involvement and nonstandard forms of interaction. As an example, the article explores the experience of elaboration and implementation of the city project “Environmental Geocaching” for the students of Tobolsk public schools. The author reviews the key stages of the game: purpose, form, brief content of training the planners and participants, examples of tasks on the example of ecological station, etc. It is believed that in the course of such events, the students learn to value the environment and its preservationt; direct participation of students at all stages of the game is a strong motivator for cognitive activity, which prompts the solutions for developmental and pedagogical tasks of environmental education. The provided methodical recommendations can be applied by the teachers in elaboration of materials for such events.