Intracranial complications of sinusitis now are unusual and subdural empyema is even more infrequent. Furthermore, subdural empyema usually is related to sinus infections, particularly those caused by Streptococcus milleri, an anaerobic organism. Although clinical suspicion is fundamental, computed tomography and magnetic resonance imaging are essential for discovering these complications. These studies enable early diagnosis and prompt treatment, thus reducing the high mortality of this disease. We report two cases of subdural empyema secondary to sinusitis in persons without impaired immunity. Streptococcus milleri was isolated in one of them. A review of the literature disclosed that this is the most frequently involved organism, so the empirical selection of antibiotics targeted this organism.