The chapter discusses the differential pulse polarographic (DPP) technique as applied to the analysis of such common antibiotics as chloramphenicol, tetracycline, streptomycin, penicillin, cephaloglycin, and neomycin. These are by no means the only antibiotics that can be analyzed, but they serve to illustrate how the technique can be applied to analysis of a variety of different structures comprising different functional groups. Viewing antibiotics in the light of the organic functional groups that they contain may seem awkward at first, but it is the key to success in a proposed DPP analysis. Some antibiotics, e.g., chloramphenicol, tetracyline, and streptomycin, contain electroactive functional groups, such as nitro functions, activated carbonyls, activated double bonds, and aldehyde groups that respond well to this method of analysis. Other antibiotics, such as penicillin and neomycin, contain no electroactive functional groups yet they are easily converted into electroactive structures through simple functionalization reactions.