To report a case of archipelago keratitis and its improvement as evaluated by corneal densitometry. A review of the patient's record and relevant literature. A 57-year-old man presented with blurred vision associated with photophobia and halos around lights. Slit-lamp examination revealed multiple confluent, nummular subepithelial infiltrates. The infiltrates were unresponsive to topical nonsteroidal anti-inflammatory drops. The treatment was changed to topical steroids and oral acyclovir and a diagnosis of archipelago keratitis was made. The patient showed quick response to the treatment and the infiltrates disappeared within 5 weeks. However, no clear changes were observed initially by slit-lamp but corneal densitometry allowed us to evaluate improvement as the density value decreased from 96.5 to 38.6. After 10 days of treatment all the symptoms were resolved. Archipelago keratitis responded well to topical steroids and oral acyclovir. We describe the use of corneal densitometry complementary to slit-lamp examination in the clinical observation of archipelago keratitis.