Purpose: To determine the causative organisms and associated risk factors for infectious keratitis in South Texas. Methods: This retrospective study was performed at a tertiary teaching hospital system in South Texas. Medical records of all patients who presented with infectious keratitis from 2012 to 2018 were reviewed. Only patients with culture-proven bacterial, fungal, and Acanthamoeba keratitis were included. Results: In total, 182 eyes of 181 patients had culture-proven bacterial, fungal, or Acanthamoeba keratitis. The age of patients ranged from 3 to 93 years, with a mean of 48. 3 ± 20. 8 years. The most common etiologic agent was bacteria, with 173 bacterial cultures (95. 1%) recovered, followed by 13 fungal cultures (7. 1%), and 3 Acanthamoeba cultures (1. 6%). Of the 218 bacterial isolates, coagulase-negative Staphylococcus was the most common (25. 7%), followed by Pseudomonas aeruginosa (23. 4%), Staphylococcus aureus (11. 0%), and Moraxella (7. 8%). Fusarium was the most common fungal isolate (46. 2%). The most common risk factors for infectious keratitis included contact lens wear (32. 4%), underlying corneal disease (17. 6%), trauma (14. 3%), and ocular surface disease (13. 7%). Conclusions: Bacteria are the most common cause of infectious keratitis in this patient population, with coagulase-negative Staphylococcus and Pseudomonas as the most common isolates. The prevalence of culture-positive fungal keratitis is significantly lower than that of bacterial keratitis. Contact lens wear is the most common risk factor associated with infectious keratitis in South Texas.