Many studies indicate that subclinical bacterial colonization plays a pivotal role in capsular contracture. Nevertheless, it has not been clarified whether bacterial stimuli are only associated with high-grade (Baker III/IV) or low-grade (Baker I/II) capsular contractures. The study included 45 female patients suffering from unilateral capsular fibrosis following augmentation mammaplasty with silicone implants (smooth: n = 28; textured: n = 17). In total, there were 16 (35.6%) bacterially contaminated swabs. No significant difference could be detected between colonization rates of smooth (52.9%) and textured (25.0%) implants (z = 1.575, P = 0.115). Interestingly, no colonization was detected for Baker I/II contractures, but the colonization rate for Baker III/IV contractures amounted to 66.7%, showing a highly significant difference between the 2 groups (z = 4.351, P < 0.001). Our study shows significant differences in bacterial contamination rates between high-grade and low-grade capsular contractures. One might speculate that bacterial stimuli accelerate the process of inflammation and fibrosis in patients who tend to develop capsular fibrosis.