Context. Circumstellar disks and outflows play a fundamental role in star formation. Infrared spectro-interferometry allows the inner accretion-ejection region to be resolved. Aims: We study the disk and Brγ-emitting region of MWC 297 with high spatial and spectral resolution and compare our observations with disk-wind models. Methods: We measured interferometric visibilities, wavelength-differential phases, and closure phases of MWC 297 with a spectral resolution of 12 000. To interpret our MWC 297 observations, we employed disk-wind models. Results: The measured continuum visibilities confirm previous results that the continuum-emitting region of MWC 297 is remarkably compact. We derive a continuum ring-fit radius of ~2.2 mas (~0.56 AU at a distance of 250 pc), which is ~5.4 times smaller than the 3 AU dust sublimation radius expected for silicate grains (in the absence of radiation-shielding material). The strongly wavelength-dependent and asymmetric Brγ-emitting region is more extended (~2.7 times) than t