The regenerative internal combustion engine is a novel concept for increasing the economy and the power output, and decreasing the pollutant emissions of the conventional reciprocating engine. This engine is based on the recovery of heat from the exhaust gases, to be utilized in the engine cycle itself. This is carried out through simple modifications to the conventional engine, affecting only the combustion chamber. In this paper, a theoretical analysis of the cycle is presented first. Recommendations are made concerning the optimum strategy to control the engine, the reduction of pollutants, and the critical design parameters. Some of the possible shortcomings of the new engine are discussed, particularly speed limitations.