We measured the low‐frequency polarized resonance Raman spectra of horse heart, chicken, and yeast(C102T) ferrocytochromes c with Soret excitation. We examined the out‐of‐plane deformations of the heme groups by determining the relative intensities and depolarization ratios of a variety of out‐of‐plane and in‐plane Raman active bands. Analysis of relative Raman intensities shows differences in non‐planarity of the heme groups of yeast(C102T), horse heart and chicken cytochrome c. Cytochrome c has been shown to have a dominant ruffling (B1u) deformation by means of normal coordinate structural decomposition (NSD) analysis of the heme group in crystal structures. The presence and intensity of B1u modes, γ10‐γ12, support the indication of ruffling being the major contribution to the non‐planar deformations in cytochrome c. Other types of non‐planar deformations like doming (A2U) and waving (Eg) can be deduced from the Raman activity of γ5 (A2u), γ21 and γ22 (Eg). The depolarization ratios of γ5, γ10, γ11 and...