Regular evaluation of environmental education is important for quality assurance and the self-assessment of educational institutions such as zoos. However, capacity is often lacking. Therefore, this study presents instruments that can be used to track the impact of educational programs on connection to nature, interest in species conservation, environmental concern, and attitude toward biodiversity loss. Questionnaires were used before (N[subscript T1] = 674) and after (N[subscript T2] = 619) different educational programs in nine different zoos. Factor analyses were conducted to control for how the scales performed in the zoo context and with visitors of different ages in a pre-post setting. The results showed that the adjusted instruments work well with a few adaptations. Interest in species conservation can be measured as an overall 6-item construct. Biodiversity loss attitude can be measured using a 5-item scale. Using a shortened version of the Environmental Motives Scale, environmental concern was found to be three-dimensional, as intended, and can distinguish effects on egoistic, biospheric, and altruistic concern in zoos. Hence, the scales presented can be used for evaluation purposes and are even applicable beyond zoos.