Sexual behavior change is needed for both the primary and secondary prevention of HIV disease. Remarkable progress has been made in modifying high-risk behaviors in selected populations (e.g., gay men living in the epicenters of the epidemic). However, many at-risk populations (e.g., gay men living outside these epicenters, homosexual men who are young or Black, ethnic minorities--especially women of childbearing age, and persons over age 50) have received relatively little research attention and may be at risk for further infection. A community-level approach to behavior change represents one kind of comprehensive strategy to achieve significant reduction in the spread of HIV. Effective approaches at this level require component interventions that are effective in changing behavior and acceptable to target populations. Also needed is an infrastructure to support behavioral change efforts. Lacking at present is a comprehensive and coordinated structure to conceptualize, stimulate, and support the continuum of behavioral research needed for the control of HIV and other sexually transmitted diseases.