OBJECTIVE The study purpose was to describe clinical nurse specialist (CNS) practice patterns (activities, outcomes, and practice barriers). METHODS A cross-sectional survey design was used for this research study. METHODS California Board of Registered Nursing certified CNSs (N = 1,523). METHODS Surveys were mailed to CNSs and included the CNS Activity Questionnaire, the Clinical Nurse Specialist Outcomes and Barriers Analysis Survey, and a demographic survey. Descriptive (means, percentages) and inferential (t tests and one-way analyses of variance) statistics were used to analyze the data. CONCLUSIONS Practicing CNSs (n = 947) demonstrated a role preference for expert clinical practice. Practice patterns (activities, outcomes, and barriers) differed in terms of CNS specialty, years of experience, number of units covered, and CNS reporting structure. Clinical nurse specialists are spending time in the 5 broad role components expert (clinical practice, consultation, education, clinical leadership, and research) utilized by the California Board of Registered Nursing as an organizing framework for practice; however, CNS practice patterns from this study reflect more discrete and functional activities that may be better encompassed under the CNS spheres of influence practice model. A number of barriers to practice exist, the most commonly reported being reporting structure. Years of experience in the role result in differences in both practice patterns and perceptions of barriers. Recommendations for CNSs and organizations include evaluating CNS reporting structures, developing advanced practice outcome-based job descriptions and competencies, and designing performance evaluations that recognize differences between inexperienced and experienced CNSs.