Background We report a clinically challenging and unusual case of L. donovani oral mucosal leishmaniasis. Case presentation Israeli resident with a former travel to central and North Africa, with no documented or prior cutaneous lesions presented with oral lesions of the maxillary gingiva and the upper lip. A delay in diagnosis and treatment have led to progression of the maxillary gingival lesions towards the hard palatal and the soft palate that could have potentially compromised the upper airway. Conclusions This case highlights the importance of early diagnosis of leishmaniasis in patients with oral lesions and the laboratory workup necessary to appropriately characterize and treat the disease.