Abstract : Meningitis is an inflammation of meanings which associated with abnormal values of cell count in the cerebrospinal fluids. Viral meningitis becomes more common after reducing in bacterial meningitis due to vaccination. Herpes simplex viruses are the second cause of viral meningitis in the developing countries. The aim of this study is to detect the incidence of HSV-1 in cerebrospinal fluid (CSF) sample of Iraqi patients with meningitis. A cross sectional study conducted from November 2019 to February 2020. Sixty out of 170 samples were enrolled in this study, all samples were collected by lumber puncture from patients who were attended the Baghdad medical city complexes. Five to twelve milliliters of CSF samples were collected for evaluation of clinical parameters of CSF samples, and for PCR detection of herpes simplex virus-1. The results of the current study revealed that HSV-1 was detected in 20 (33.3%) out of 60 Iraqi patients with meningitis. The present study concluded that HSV-1 may have an important role in the development of meningitis in Iraqi patients