Introduction: Breast implant infections are feared complications in aesthetic as well as in reconstructive breast surgery. They are associated with high costs for the healthcare system and suffering for the patients. Adequate infection prevention starts with an understanding of the causative pathogens. Therefore, the objective of this study was to analyze possible differences in the microbial spectrum of implant infections after breast augmentation and after breast reconstruction. Materials and Methods: For the period from January 2001 to December 2019, patients who received medical care from the Department of Plastic and Reconstructive Surgery of the Vienna General Hospital, due to a breast implant infection, were retrospectively analyzed. All data was collected using the documentation system of the Vienna General Hospital. A total of 28 patients were included. Results: In total 28 breast implant infections occurred: 15 after reconstruction and 13 after augmentation. A smear test was obtained in 25 patients. 17 cultures showed bacterial growth. A total of 22 germs, including 11 different bacteria, were detected. The three most common pathogens were Staphylococcus aureus n=4 (24%), Pseudomonas aeruginosa n=4 (24%) and Staphylococcus epidermidis n=4 (24%). Staphylococcus aureus was detected more frequently in the augmentation group than in the reconstruction group (33.3% vs. 12.5%, p>0.312). The incidence of gram-negative bacilli was greater under the augmentations than under the reconstructions (50% vs. 30%, p>0.342). Anaerobic bacteria, on the other hand, were found less frequently in augmentation patients (33.3% vs. 62.5%, p>0.229). There was a slight difference in bacteria that occur in the physiological skin flora (66.7% vs. 50%, p>0.486). Conclusion: Differences in the pathogens of implant infections in reconstruction patients and augmentation patients could be shown. However, these results showed no statistical significance. Nevertheless, these findings could help to adapt strategies for prevention and treatment of implant infections in future patients.