This article reviews the present situation in the field of turbo-blowers for 2-stroke diesel engines. The author first presents some theoretical considerations to outline the problems with which the designer of turbo-blowers for 2-stroke diesels is confronted mainly in view of the required pressure gradient between the turbine and compressor and attention to the surging limit. He then describes the two supercharging principles employed: constant pressure with scavenging pumps in series with the turbo-blower, and pulse operation with pumps in parallel, discussing their advantages and drawbacks, and finally deals with engine design, test and operating results.