Although individuals' self-reports of behaviour are often used as a proxy for household environmental outcomes, little is known about how accurate they are or what factors might moderate accuracy. The current research investigated this question in relation to household recycling and water use. Results of Study 1 showed a significant, albeit weak, relationship between self-reported household recycling and objective measure of recycling that was not moderated by the number of people in the household. There was some evidence though that the relationship between self-reported and objective household recycling was stronger when respondents perceived more supportive community norms for recycling. The results of Study 2 supported Study 1 in showing a significant but weak relationship between self-reported water conservation behaviour and objective household water use that was again not moderated by the number of people in the house. Similar to Study 1, Study 2 showed that there was a stronger relationship between self-reported and objective behaviour when respondents had more favourable attitudes, more supportive subjective norms, and greater self-efficacy in relation to water conservation. Taken together the research suggests that psychological variables that orient householders to environmental behaviour are more important influences on aligning self-reported behaviour with objective outcomes than knowledge about the behaviour of others in the household.