Objectives: To review developmental abnormalities and iatrogenic alterations in sinus anatomy that may predispose patients with congenital craniofacial malformations to chronic rhinosinusitis. Study design: Retrospective study. Methods: Seven patients with craniofacial malformations who were surgically treated by the senior author were included in the study. All were diagnosed with chronic rhinosinusitis refractory to medical management. Four patients had undergone previous corrective craniofacial surgery, and three of these patients developed iatrogenic sinus disease. Demographic data, diagnoses and anatomical abnormalities were included. Results: Abnormal sinus anatomy was present in all patients, most commonly skull base abnormalities and dehiscent lamina papyracea. All patients underwent successful endoscopic surgical management (n = 7) for their chronic rhinosinusitis. Two patients had adjuvant external procedures. There were no complications and no recurrences after a mean follow up time of 15 months. Conclusions: Otolaryngologists should be aware of the possibility of chronic rhinosinusitis in patients with craniofacial malformations. Careful preoperative evaluation of radiographic studies should be performed as most of these patients will have abnormal sinus anatomy. In addition, patients who undergo surgery to correct their craniofacial malformations are susceptible to altered sinus anatomy that may predispose them to the development of iatrogenic chronic rhinosinusitis. © 2005 Elsevier Ireland Ltd. All rights reserved.