Public managers play a critical role in making and implementing environmental policies. Pre-service training provides an important opportunity to influence the environmental attitudes of public managers. Nevertheless, we know little about this influence. This research employs a classic experiment to examine the effects of a pre-service training program that exposes trainees to ecological decline in a national training program in Taiwan. There are three major findings. First, exposure to ecological decline increases trainees' pro-environmental attitudes. Second, visual presentation modes sustain the effect. Third, trainees highly motivated for public services demonstrate greater and longer-lasting pro-environmental attitudes due to ecological exposure. These findings can be used to develop and improve environmental education programs in governments.