Since the advent of supporting matrices for biological applications, many types of drugs have been administered via various forms of conventional drug delivery preparations, such as pills. solutions, creams, suppositories, injected gels, and so on. Key parameters to all these systems for effective drug delivery are controlled release for sustained periods, targeted delivery, and enhancements of drug stability and efficacy, all of which can be manipulated by using polymers. Given the important impact of the structures of the polymers on these parameters, this mini-review gives a simple introduction to the requirements of drug delivery systems and surveys the synthetic pathways to a key polymer in this field, namely poly(lactic acid) (PLA). We also review the preparation of block copolymers that incorporate PLA, to expand and further develop its properties for drug delivery systems. It is hoped that this short teacherly and introductory review will provide a basic stepping-stone to more in-depth reviews and papers, and enable an easy access to this fast growing field.