Minute pieces of debris left in the surgical site can interfere with optimal wound healing. Even when these microbodies are not obvious without magnification, their presence can cause post-surgical complications including infections, amplified and prolonged inflammation, permanent tissue damage, exaggerated and reduced quality scarring, granulomas, adhesions, organ dysfunction, infertility, and other pathological consequences. This chapter reviews foreign debris-initiated, post-surgical complications; presents associated pathological mechanisms; identifies sources of debris contamination; describes foreign-microbody characteristics that can further amplify pathological responses; and presents recommendations for minimizing their presence.