Effective use of educational technologies by teachers in classrooms has come into prominence as the integration of technology into educational settings in todays world is considered as an inseparable part of an effective teaching. Besides, recent teacher training curriculums too emphasize the use of teaching strategies including technology to enhance student achievements. For this reason, it is decided to design a research focusing on to the use of an educational technologies based triadic teaching approach in teaching some environment-related subjects (global warming, ozone layer, air pollution, acid rains) of the science curriculum with 30 prospective science teachers through the special teaching methods course. The triadic teaching approach is comprised of internet-web based online research, poster preparation process activities and mini symposium activities steps. In order to establish the effect of the triadic teaching approach in selected environment-related subjects to meaningful learning of students, a pre and post word association test has applied, concept network maps of prospective teachers were drawn performed with them to collect their opinions on the triadic teaching approach. Findings of the study revealed that the triadic teaching approach has contributed to meaningful learning and ability of utilizing educational technologies of prospective teachers.