A method is described for diagnosing errors in an internal combustion engine in which fuel is injected from a high-pressure accumulator into associated combustion chambers with the aid of multiple fuel injectors, a first value (Rstat,2) which is representative of a static flow rate of fuel through one of the fuel injectors being ascertained, a second value (Δn) which is representative of a running smoothness of the internal combustion engine being ascertained, if at least one of the two values (Rstat,2, Δn) deviates from the particular associated reference value (R′stat, Δn0), an error (F) being deduced, and the error (F) being assigned to the fuel injector and/or at least one further component and/or at least one operating phase of the internal combustion engine on the basis of deviations of the two representative values (Rstat,2, Δn) from the particular associated reference value (R′stat, Δn0).