Human values and attitudes have been presented as important variables associated with behaviour that has an impact on the environment. Despite these evidences, there is still need to clarify the relationship between values, attitudes and pro-environmental behaviour, and to distinguish between environmental and altruistic values and attitudes and their effects on pro-environmental behaviour. The study presented here examines, in two methodological approaches (experimental and correlational), the role that environmental and altruistic values may assume in the prediction of attitudes and pro-environmental behaviour. The experiment, where 116 individuals participated, tested the effect of the activation of situational cues on energy saving behaviour, using conceptual priming with four conditions: environment, altruism, environment plus altruism, and control. After participate in the experiment, participants were allegedly conducted to another study that was in fact a questionnaire designed to allow the analysis of how environmental and altruistic values affect pro-environmental behaviour intentions (recycling and energy saving) and how this is mediated by environmental and altruistic attitudes.The experiment data analysis showed that priming had a significant effect on energy saving behaviour. Participants displayed more this type of behaviours when they were primed with environment, altruism, and environment plus altruism cues. For participants with environmental values, energy saving behaviour tended to be higher in the environment priming condition, while for participants with lower environmental values energy saving behaviour tended to be higher in the altruism and environment plus altruism priming conditions. This indicates that pre-existing environmental values seem to affect the extent to which the situational activation of cues affects energy saving behaviour. Regression analysis of the questionnaire data showed that environmental values contribute significantly for the explanation of recycling behaviour intention and, on the other hand, energy saving intention is predicted by altruistic values. However, these effects of values on behaviour intentions are not mediated by environmental or altruistic attitudes, despite some associations found between attitudes and behaviour intentions.The results from the study show the importance of the distinction between environmentalism and altruism in the explanation of pro-environmental behaviours and intentions.