PURPOSES:A literature review to describe the current diagnosis and management of Acanthamoeba keratitis. RESULTS:Acanthamoeba is a ubiquitous protozoan8 species, 5 genotypic classes have been reported to cause keratitis. It is potentially a sight-threatening infection, and there is often a poor prognosis because of a significant delay in diagnosis and frequently a lack of effective medical management. Main risk factors are contact lens wear, poor hygiene, and contact with contaminated water. Current methods of diagnosis include corneal scrapings for histopathologic analysis, tissue culture, confocal microscopy, and polymerase chain reaction (PCR), each are reviewed in turn. Treatment options include medical (biguanides, diamidines, and corticosteroids) and surgical (epithelial debridement, amniotic membrane transplant, and penetrating keratoplasty). CONCLUSIONS:Early diagnosis and treatment are required to effectively manage this condition.