This case report describes a 33-year old woman admitted with sepsis 6 days post partum. No infectious focus was revealed at initial examination. The patient responded moderately to intravenous antibiotics. Positive blood cultures, a systolic murmur and echocardiography revealed severe pneumococcal endocarditis, necessitating surgery. The patient fully recovered. Endocarditis is a rare post partum complication. This case report demonstrates the need for aggressive re-evaluation and involvement of other specialists when the patient does not respond to antibiotic therapy.