We introduce an optical microscopy technique that utilizes micro- or nanolasers embedded in a sample as imaging probes. The narrow spectra and nonlinear power dependence of stimulated emission from the laser particles yield optical sectioning, subdiffraction resolution, and low out-of-focus background. A proof of concept is demonstrated using perovskite nanowires. ; National Science Foundation (U.S.) (Grant ECCS-1505569) ; National Institutes of Health (U.S.) (Grants DP1EB024242 and P41EB015903) ; Massachusetts General Hospital. Research Scholar Award Program