Purpose To report a case of atypical herpes simplex keratitis initially diagnosed as bacterial keratitis, in a contact lens wearer. Results Case report of an 18-year-old woman using contact lenses who presented with pain, redness and gradual decrease in vision in the right eye. Examination revealed a paracentral large stromal infiltrate with a central 2-mm perforation. Corneal and conjunctival scrapings were collected for microbiological investigations. Corneal tissue was obtained following penetrating keratoplasty. Corneal scraping revealed no microorganisms. Giemsa stained smear showed multinucleated giant cells. Conjunctival, corneal scrapings and tissue were positive for herpes simplex virus - 1 (HSV) antigen. Corneal tissue was positive for HSV DNA by PCR. Conclusions Atypical HSV keratitis can occur in contact lens wearers. A simple investigation like Giemsa stain may offer a clue to the diagnosis.