Violence in the workplace is an increasing occupational health concern worldwide. Health care workers are at high risk of assault. To develop, monitor, and manage prevention policies, baseline data should be available. This cross-sectional study was designed to determine the current extent of workplace violence nationwide in Turkey. The study population of 12.944 health care workers was a stratified sample of all health care workers (612,639) in the country. A probabilistic sampling was made on the basis of the "multistage stratified random cluster sampling method." This study was conducted by a structured questionnaire in a face-to-face interview. The questionnaire items were adapted and translated into Turkish based on questionnaires of International Labor Organization, International Council of Nurses, World Health Organization, and Public Services International. The percentage of health care workers who experienced workplace violence in Turkey in the previous 12 months was 44.7%. The types of violence included physical 6.8%, verbal 43.2%, mobbing (bullying) 2.4%, and sexual harassment 1%. Multivariate analysis showed that level of health care system, type of institution, gender, occupation, age, working hours, and shift work were independent risk factors for experiencing workplace violence (p < .05). Our study indicates that the workplace violence among health care workers is a significant problem. The results of the study can serve as the basis for future analytical studies and for development of appropriate prevention efforts.