Step fluctuations have been studied on Mo(011) thin single crystal films with various orientations of miscut, in order to determine the step stiffnesses. Measurements of fluctuation amplitudes and relaxation times were made in the temperature range 1080–1680 K. Surface diffusion Ds is documented at T/Tm~0.5, while the crossover to relaxation driven by bulk vacancy diffusion is inferred for T/Tm~0.6. Here, Tm is the melting temperature Tm = 2896 K. We obtain Ds = 4x10-4 exp(-1.13 eV/kBT) cm2/s for the temperature interval above. Possible indications of diffusion along step edges appear for T/Tm~0.4. Additionally, the results show an anisotropic stiffness of about 0.36 eV/nm along [0-11] and about 0.15 eV/nm along [100]. No temperature dependence of the stiffness was detected. The step free energies derived from the stiffnesses average about 0.27 eV/nm and are less anisotropic by about a factor 3. It is shown that three independent procedures yield mutually consistent step stiffness anisotropies. These are (1) step fluctuation amplitudes; (2) step relaxation rate anisotropies; and (3) the observed anisotropies of islands in equilibrium on the Mo(011) surface. The magnitude of the step stiffness obtained from step edge relaxation is consistent with earlier measurements that determine diffusion from grain boundary grooving.