**Abstract**

Cardiovascular diseases are the most leading cause of worldwide mortality. According to USA statistics, about 1 of 6 cardiovascular deaths is due to stroke. Stroke is the second most common cause of death and a chief cause of disability due to EU data. Treatment, care providing, rehabilitation costs and with the labor loss, the overall cost in EU due to stroke was estimated about €45 billion in year 2017. Acute stroke due to infectious diseases *via* several possible mechanisms with various clinical presentations were previously reported in the literature. *Chlamydia pneumoniae* is an obligate intracellular bacteria and extremely common in adult individuals. Besides it being a major cause of pneumonia in adults, association between atherosclerosis and vascular diseases was demonstrated by several sero-epidemiological studies and by direct detection of organism in atherosclerotic lesions by electron microscopy, immunohistochemistry, polymerase chain reaction. Also, several sero-epidemiological studies have demonstrated a link between *Chlamydia pneumoniae* infection and acute stroke. In this chapter, we will summarize the data in literature regarding the association between *Chlamydia pneumoniae* infection and acute stroke and we will try to explain the possible mechanisms that could be responsible in pathophysiology of stroke in these patients.

**Keywords:** Chlamydia pneumonia, stroke, atherosclerosis, cerebral infarction, acute stroke
