OBJECTIVE The frequency of maxillary sinusitis of dental origin (MSDO) is under estimated. The medical and surgical treatment has improved thanks to endoscopic guidance. We report our experience and strategy in the treatment of MSDO. METHODS Twenty-two patients presenting with MSDO were treated between 1998 and 2008. The results were evaluated on clinical, functional, sinusal, and odontologic signs. RESULTS MSDO accounted for 16% of surgically managed sinusitis. CT was performed in 95% of cases. The etiologies were apical leakage in seven patients, migration of a tooth or root during extraction, or presence of ectopic tooth in the sinus in nine patients, a cyst in three patients, and oroantral communication in three patients. Surgery was performed after antibiotic and NSAID treatment. The first surgical step was the treatment of the odontogenic source. The second step was sinus drainage by endoscopic treatment in 64%, Caldwell-Luc in 23%, and drainage by oroantral communication enlarged then closed in the same operative time in 13%. The follow up ranged from 3 months to 10 years. Early postoperative superinfection was observed in two patients. Two patients presented with recurrent sinusitis. The postoperative sequels were hyposmia in three patients, dental pulpotomy, and trigeminal neuralgia in five patients treated by Caldwell-Luc surgery. CONCLUSIONS Nasal endoscopy has improved the surgical management of MSDO. It makes curettage and exclusion of sinus cavities obsolete. It is reliable and has a low rate of complications. The best treatment remains prevention.