Oroantral fistula (OAF) and oral candidiasis are common to come across as separate individual lesions. However when candida organisms infect maxillary sinus through OAF then diagnosis should not be limited to clinical diagnosis only. In such situation role of cytological examination can prove to be fruitful. A female with chronic long standing OAF, not responding to conventional treatment approach is reported. On incisional biopsy, the case was diagnosed as chronic maxillary sinusitis with OAF. However patient did not respond to any treatment approach and later presented with a more progressive lesion involving maxillary sinus. A cytosmear stained with periodic acid Schiff stain, revealed the presence of numerous candidal hyphae. Finally, case was diagnosed as OAF with a superadded candidal infection. Patient responded well to antifungal treatment followed by reclosure of OAF. We should not neglect a simple cytological examination which may prevent wrong diagnosis and wrong treatment.