Purpose. To present a case of infectious keratitis caused by the microorganism Serratia marcescens in a contact lens user and further to confer on the most advantageous management of comparable situations. Case. After altering the routine that she used for contact lens disinfection, a 24-year-old patient presented with pain and conjunctival redness in both eyes. Slit-lamp examination revealed two infiltrates in the inferior part of the cornea in the right eye and five smaller infiltrates in the superior half of the left cornea. Appropriate treatment, after hospitalization, improved the symptoms while culture of the contact lens material revealed Serratia marcescens as the responsible infectious factor. Conclusion. Enhancing the availability of information with respect to contact lens users and customized analysis regarding treatment for a particular complication could be beneficial in order to reduce the frequency of admission to the eye clinic due to infectious keratitis. In addition, rapid laboratory testing of the infected materials should be a priority for selection of the optimal treatment regimen.