Abstract We investigated micro-cylinder lasers that were processed from a quantum cascade heterostructure. In particular, we compare the lasing performance of micro-cylinders with Fabry–Perot resonators and with distributed feedback lasers. The three types of cavities were processed from the same GaAs/Al 0.45Ga 0.55As superlattice structure. We find that the threshold at low temperatures for both micro-cylinder and distributed feedback lasers is decreased by a factor of 2 below that of the Fabry–Perot laser. The maximum operating temperature of the micro-cylinder is 54°C. In addition, we present data of the first quantum cascade ring laser.