Leaders of the National Academy of Neuropsychology and Division 40 (Clinical Neuropsychology) of the American Psychological Association determined that current information on the professional practice of clinical neuropsychology within the United States (U.S.) was needed. These two organizations co-sponsored a national survey of U.S. clinical neuropsychologists that was conducted in September 2000. The primary goal of the survey was to gather information on such topics as: practitioner and practice characteristics, economic variables (e.g., experience with major third party payors, such as Medicare and managed care), practice expenses, billing methods, experiences with Current Procedural Terminology (CPT) codes, time spent on various clinical tasks, use of assistants, and income. The adjusted return rate of 33.5% (n = 1,406) reflects the number of surveys returned with sufficient data by licensed doctoral level clinicians with membership in one or both sponsoring organizations. In this first of two articles describing the survey results, characteristics of practitioners and practices, various types of professional activities, and time requirements for clinical tasks are presented and discussed. It was noted that the proportion of women in the field is increasing rapidly. Private practice is the predominant employment setting. Findings also document that members of the two sponsoring organizations are very similar with regard to employment setting, professional characteristics, and weekly activities. That is, involvement in clinical practice and research, as well as private practice versus institutional employment, was very similar between organizations. However, across organizations, work setting (private practice vs. institution) was associated with significant and meaningful differences. Private practitioners have a more diverse set of weekly clinical activities, are less likely to use assistants, and engage in more forensic activities. Across work setting, with the exception of forensic evaluations, those using assistants invest a greater number of hours per evaluation, but bill approximately the same numbers of hours per evaluation.