Three experiments were conducted concerning the effect of attention to positive or negative images of the physical environment on altruistic behavior: I. Some subjects listed and described aspects of their residential environments that were particularly pleasant while others described particularly unpleasant aspects. II. Subjects were exposed to slides of either attractive or unattractive outdoor environments. III. Subjects viewed slides of either attractive or unattractive environments while adopting an attentional set that focused only on positive or negative aspects of the slides. After these manipulations, subjects in each experiment encountered an ostensibly unrelated confederate who sought their assistance as a favor. Experiment I subjects who had thought about pleasant environments spent significantly more time helping than those who thought about unpleasant enviornments. Experiment II subjects who saw slides of attractive environments offered significantly more aid for a longer time period than subjects who saw slides of unattractive environments. Experiment III subjects who focused on positive aspects of attractive enviornments gave more help than subjects who focused on negative aspects of attractive environments, though overall differences were not significant. Attentional set produced no differential helping effects in subjects who had viewed unattractive environments. In all three experiments mood or affect was discussed as mediating the impact of environments on behavior.