We present a case of frontal sinusitis complicated with a subdural empyema, in 
which the identified microorganism was Gemella morbillorum, a frequent host of 
the aerodigestive tract and occasionally related to infections. The problem was 
resolved successfully using endoscopic surgery and an external approach of the 
sinus. Afterwards it was completed with a subdural drainage through craniotomy. 
Subdural empyema is a rare complication of sinusitis although very severe. We 
want to emphasize the importance of early diagnosis of intracranial 
complications, the need of a detailed microbiology test the method used to 
obtain samples, and the convenience of a combined approach by the 
otolaryngologists and the neurosurgeons for its complete drainage.