Under usual conditions the domain configuration in rare‐earth orthoferrites shows no contrast by x‐ray diffraction topography. In the reorientation range of temperatures, where the net magnetization rotates away from thecaxis, the domain configuration is favorable for x‐ray observations. Domains have been revealed in a cobalt‐substituted orthoferrite where the reorientation range is at room temperature. The observed contrast does not obey the simple rules that apply to similar observations in Fe&sngbnd;Si and YIG. Possible reasons for the observed contrast are discussed in terms of the domain distortion.