The Penicillium genera, encompassing about 225 different species of fungi, are naturally present in the environment. These genera are poorly linked to human disease, except for Penicillium marneffei causing septicemia in immunocompromised hosts. Thus, Penicillium species recovered from respiratory tract samples are often considered as inhaled contaminants in the clinical laboratory. However, we report here a case of fungal maxillary sinusitis due to Penicillium roqueforti diagnosed in a 40-year-old female, a teacher, complaining of moderate pain for months in the maxillary sinus and chronic posterior rhinorrhea. CT scanner and MRI enabled a preliminary diagnosis of left maxillary fungus ball-type sinusitis with calcified material seen on CT and marked very low signal in T2 weighted images seen on MRI. Anatomopathological and mycological examination of sinusal content showed septate hyphae. Direct sequencing of the sinusal content revealed P. roqueforti. P. roqueforti has been traditionally used in France for more than 200 years for cheese ripening. However, to our knowledge, this ascomycetous fungus has very rarely been associated in the literature with human disease. P. roqueforti is associated only with cheese worker's lung, a hypersensitivity pneumonitis affecting employees in blue cheese factories. Other species in the Penicillium genus are reported to cause various disorders such as invasive infection, superficial infection or allergic diseases. P. roqueforti has never previously been reported as a cause of human infection. Thus, we report the first case of fungus ball due to P. roqueforti in an immunocompetent patient.