the oroantral fistula is a pathological connection between the maxillary sinus and with the oral cavity. the condition mostly follows dental extraction. aim: to present the experience of 25 cases. material and methods: retrospective cases between 1996-2000. the orl examination included nasal or sinusal endoscopy, a ct scan and histopathological analysis. results: twenty-five cases were found: ten 2nd molar cases, eight 1st molar cases, six 2nd premolar cases, and one canine case. all patients underwent a caldwell-luc operation plus excision of the epithelium lining the fistula, that was then completely covered by a flap of mucosa rotated from the genian region. discussion: in cases of major fistulae a bone autograft taken from the anterior sinus wall was used. bacterial cultures (n=19) revealed streptococus pneumoniae (13), haemophillus influenza (6), moraxella catharralis (2) and staphylococus aureus (2). aspergillus niger was found in one case presenting as a "fungic ball". conclusions: the only case of surgical failure, after 30 days postoperatively, was reoperated, using a bone graft. after a 6-month follow up all of the patients progressed satisfactorily, including the reoperated patient.