Objectives. This study aims to examine the frequency of exposure of health care providers to aggression and violence at work, and the effective factors thereon, as well as the effects of violence on health care providers. Materials and Methods. This cross-sectional type study has been conducted in Istanbul Training and Research Hospital (IEAH) (219) and Bayrampasa State Hospital (BDH) (64) in April 2010. The questionnaire prepared by researchers has been filled in through face-to-face meetings with a total of 283 health care providers, who accepted to take part in the study. The resulting data have been assessed and evaluated through SPSS 11.5 package program. Results. 66.8% of the respondents reported that they had been exposed to violence and aggression during the recent one year, the most frequent type thereof being verbal violence (86.8%). 90.2% of the health care providers exposed to violence at work stated that the applicable current laws do not protect the staff against violence, and 88.3% thereof stated that their institution have not supported them upon an act of violence. A statistically significant difference in the frequency of exposure to violence has been detected between age, seniority at work, place of exposure to violence, and profession of the health care staff (p< 0.05). Approximately half of the health care providers opine that their behavior towards patients has been negatively affected from violence. It is noted that such negative behavior change is even higher in females, staff with a frequency of violence > 5, assistants, and staff who believe that security at work is at risk in their institution (p< 0.05). Conclusions. Around 1/3rd of the health care providers have reported that they have been exposed to violence at least once during the recent one year, and half of those exposed to violence have stated that their behavior towards patients has been negatively affected therefrom.