Abstract
Infective endocarditis mainly affects the heart valves, and produces a primary lesion known as vegetation. 50% of patients that develop this disease do not have associated risk factors. Clinical manifestations are variable, nevertheless the most frequent ones are fever, anemia and the development of a new heart murmur or the aggravation of an old one. The clinical evolution of endocarditis depends on the microorganism causing it; usually is caused by a Streptococcus spp. or Staphylococcus aureus. In the elderly and immunodeficient patients, Streptococcus gallolyticus is most common pathogen. Neurological complications are the most common and serious complications of infectious endocarditis. Within these, mycotic aneurysm presents a high mortality rate, up to 60-80%. The present article discusses the case, of a young patient without know risk factors who developed an infectious endocarditis due to Streptococcus gallolyticus and presents a mycotic aneurysm as a complication.