Biodegradable biopolymers attract much attention in biology and medicine due to its wide application. The present review is designed to be a comprehensive source for research of biodegradable and biocompatible bacterial polymer, poly(3-hydroxybutyrate). This paper focuses on basic properties of biopolymer: biodegradability and biocompatibility, as well as on biopolymer systems: various materials, devices and compositions on the basis of biopolymer. Application of biopolymer systems based on poly(3-hydroxybutyrate) in medicine as surgical implants, in bioengineering as scaffold for cell cultures, and in pharmacy as drug dosage forms and drug systems is observed in the present review.