A method is described for operating an internal combustion engine, having a plurality of cylinders in an homogeneous operation, in which an exhaust gas lambda value and an unsteady running of the internal combustion engine are recorded, a mixture composition being cyclically varied, at least intermittently. In a test operation, the mixture composition is cyclically varied, in a selected cylinder, about a determined lambda value, whereas meanwhile the mixture composition is held constant in the remaining cylinders. From the magnitude of a cyclical fluctuation of the unsteady running or of a variable characterizing this, one may conclude upon a trimming of the mixture composition in the selected cylinder.