Despite the extant literature that discusses the potentiality of environmental identity in shaping people’s engagement with nature, there is little evidence of which specific domains of environmental attitudes and knowledge are connected with environmental identity. The present article reports on the results from two studies that were conducted within the framework of the Solomon four-group design, in four randomly selected teacher colleges (TCs) in Tanzania. Specifically, study one was an intervention with pre- and post-measurements that involved indoor and outdoor environmental programs among pre-service biology teachers in two TCs. Moreover, study two was conducted in two other selected TCs, with a post-test only. The two-Major Environmental Values (2-MEV) and a Competence Model for Environmental Education were used for measuring environmental attitudes and knowledge, respectively. Finally, environmental identity was measured using the environmental identity (EID) scale. The results revealed that preservation was positively correlated with domains of identity, while other variables demonstrated overlapping relationships in different measurement points. Moreover, notable correlations between social desirability responding with some domains of attitudes and identity were evident, whereas the age of respondents had limited associations with other variables. The article concludes by proposing the need to promote environmental attitudes (EA) and knowledge as important strategies in fostering environmental stewardship.