Biodiversity loss induced by human activities has become an urgent environmental problem worldwide. Conservation is the main pathway to reducing biodiversity loss. According to the Cambridge Conservation Forum, successful conservation implies improvements to the opportunities of enhancement of ecosystems, habitats, species, and populations in the wild, without harmful effects on human well-being. Since the human induced impacts on biodiversity are related to every action of each living person, the goal of conservation cannot be achieved without the public’s participation. Conservation education is the most important method to transmit conservation concepts to the public. It aims to arouse the public’s awareness of biodiversity issues and inspire conservation attitudes and behaviour. Many zoos and aquaria now claim that they are important avenues for informal conservation education, and as animal themed attractions, they do have the potential to involve more citizens in becoming conservation champions. Some research has evaluated the output of conservation education in zoos and aquaria, showing that the effectiveness of conservation education does not appear to be successful enough. However, few studies have examined at the interpretation content provided by zoos and aquaria. Therefore, this research was conducted to understand the content of interpretation and conservation education in zoos and aquaria. Auckland Zoo and SEA LIFE Kelly Tarlton’s Aquarium were chosen as two research cases, since they represent different types of animal based attractions. The research questions of this research were: 1) what conservation education content has been provided to the public in zoos and aquaria? 2) how does the content reflect the organisational missions and their conservation work? and 3) how does conservation education in zoos and aquaria influence visitors’ opinions after their visit? To answer these questions, this research collected data from three different sources, adopting three different kinds of qualitative research methods. First, photos of interpretation materials at the two case study sites were collected and analysed using content analysis. Second, textual material on the official websites of the two organisations was collected and analysed through thematic analysis, and third, visitor reviews of the two attractions on TripAdvisor were collected and analysed employing netnography. The NVivo program was used to assist with the analyses. The main findings of the interpretation content of the two attractions showed that 1) conservation issues were not the dominant category of the interpretation; 2) the interpretation may contribute to conservation education; 3) the content of interpretations reflected the organisational missions and the organisations’ conservation work; 4) visitor reviews showed that the content of interpretation can influence visitors’ opinions after their visit; and 5) conservation education of the two attractions was partially successful. This research also discusses the role of interpretation content in conservation education in zoos and aquaria, and argues that interpretation content can influence visitors’ conservation learning both directly and indirectly. It is suggested that to improve conservation education in zoos and aquaria, the attractions should adjust their understanding of conservation to that of conservation science. This research also proposes a model for better conservation education design adjusted from Orams’ (1997) model, emphasising the content of interpretations.