Based on the ecological scale of Maloney et al. (1973, 1975), the present study is aimed to test the relationship between environmental attitudes and behaviour in a more rigorous manner. In doing so, 552 Hong Kong citizens were interviewed and several salient findings were generated. First, along with what is proposed by literature, verbal commitment was found to be the most immediately relevant predictor for one's self-reported actual environmental behaviour. Second, when compared between knowledge and affect, the latter was noted to be far more powerful in explaining the self-reported actual environmental behaviour. This highlights that the government should rely more on emotional than cognitive appeal for spelling out environmental messages. Lastly, the findings also suggested the inclusion of other non-attitudinal factors for predicting the environmental behaviour.