The objectives of this study were to assess the effects of the Home Energy Audit Program on the conservation behavior of participating households and to test a model of energy conservation behavior. The computer-assisted program was developed by the Iowa State University Extension Service and was used to audit approximately 10,000 houses between 1977 and 1981;Mail surveys were used to obtain data (N = 526) from randomly selected audit participants and a statewide group of home owners. Respondents were asked to report structural improvements they had made between September 1977 and May 1981. Three-fifths of the control group and almost three-fourths of the audit group made one or more capital improvements to increase the energy-efficiency of their homes;Installation of basement and crawl space insulation revealed significant differences between the two groups. More than twice as many audit participants insulated these areas as the control group. Much of this differential behavior was attributed to knowledge gained about the relative merits of various energy-conserving innovations from participating in the Home Energy Audit Program;A diffusion-of-innovations framework was used to investigate the factors that contribute to the implementation of energy-conserving innovations: contact with change agents, perceived attributes of innovations, household characteristics, and felt needs or problems. The data supported the hypothesis that conservation behaviors involving improved efficiency are different from those representing curtailment actions. Younger households, households that were more connected with others in the social system, and households that were experiencing problems with the current energy situation, were more likely to make structural changes to improve the energy-efficiency of their homes;By contrast, significant predictors of energy-curtailment improvements included the perceived compatibility of personal comfort with an energy-conserving lifestyle and actively seeking energy information from mass media sources. An economic rationale serves as the underlying theme in the efficiency innovations model, while personal comfort overshadows economic considerations in the curtailment innovations model.