Keratitis is a frequent pathology in everyday ophthalmology, whose etiologies are dominated by bacterial origin. The mycotic origin is a rare cause, and the prognosis is usually reserved, given the delay in diagnosis, mainly due to self-medication. We present a case report concerning a 60 year old patient who presented a mycotic corneal abscess due to Alternaria sp . He presented a stromal infiltration of the cornea of the left eye on biomicroscopic examination. A swab of the abscess was performed for mycological study which came back positive for Alternaria sp . On the basis of the clinical manifestations and conducted examinition, a diagnosis of Alternaria mycotic keratitis was established.