Purpose Percutaneous endoscopic gastrostomy (PEG) is frequently used to provide enteral access in cancer patients who are unable to swallow. Infection is an important complication in this setting. Current microbiological data are needed to guide infection prevention and treatment strategies. Methods The microbiological records of our institution (a 550-bed comprehensive cancer center) were retrospectively reviewed over an 8-month study period in order to identify patients who developed PEG tube insertion site infections, and review their microbiological details and susceptibility/resistance data. Results Fifty-eight episodes of PEG tube insertion site infections were identified. Of these, 31 (53%) were monomicrobial, and the rest were polymicrobial. The most common organisms isolated were Candida species, Staphylococcus aureus, and Pseudomonas aeruginosa. All infections were local (cellulitis, complicated skin, and skin structure infections including abdominal wall abscess) with no cases of concomitant bacteremia being documented. Most of the organisms isolated were susceptible to commonly used antimicrobial agents, although some quinolone-resistant and some multidrug-resistant organisms were isolated. Conclusions This retrospective study provides descriptive data regarding PEG tube insertion site infections. These data have helped us update institutional guidelines for infection prevention and treatment as part of our focus on antimicrobial stewardship.