I. INTRODUCTION Bessel beams [1–3] are a family of nondiffracting waves propagating in dielectric media along for instance the z -axis with a homogeneous spatial variation exp ( iβz ) but transversally localized around its focus , say r = 0. For a zero-order Bessel beam, the transverse pattern is written in terms of the radially-symmetric function J$_{0}$ ( k$_{⊥}$r ). They are interpreted as a suitable superposition of plane waves all having a wavevector which projected onto the propagation axis yields the characteristic propagation constant β > 0 of the Bessel beam [4, 5]. A phase matching condition at focus is additionally satisfied in order to provide the best spatial localization of the wave in the vicinities of such an axis. The FWHM of the Bessel beam is 3 . 04 k − 1 ⊥ , which increases along with the propagation constant in accordance with the dispersion equation k 2 $_{⊥}$+ β 2 = n $^{2}$k2 $_{0}$, being n is the index of refraction of the medium and k$_{0}$ = 2 π/λ$_{0}$ the wavenumber in vacuum. Therefore the minimum beamwidth, roughly given by λ$_{0}$/ 2 n , is reached in the stationary-wave limit β = 0. This sort of solutions of the Helmholtz equation may be found also in stratified media if the unit vector ( n ) normal to the interfaces lies along the z -axis leading to normal incidence of the wavefield [6–9]. However, out-of-plane excitation cannot support the invariant prop- agation of Bessel beams [10]. For example, assuming the medium is periodic, the elements of any wave superposition are necessarily Bloch modes leading to a significant asymmetry in the resultant pattern. Provided the projection β of the pseudomoment along a direction perpendicular to the periodicity of the medium coincides for all Bloch components we may have a nondiffracting localized beam if, additionally, the phase matching condition is satis- fied [11]. With dielectric slabs, we encounter a higher localization of the field for decreasing values of the propagation constant β . This is also reported in two-dimensional photonic crystals [12, 13], being observed not only under subdiffractive light propagation [14] but much more generally. In this paper we study the formation of localized waves which propagation is resonantly sustained on a given interface from a 1D periodic metallo-dielectric medium. The surface resonance arises in transverse-magnetic waves ( H ⊥ n ) provided the sign of the dielectric constant changes abruptly at both sides of the interface. The excitation of such surface plasmons polaritons (SPPs) are attained at comparatively high values of β , however leading to a subwavelength beam size. In spite of such an extreme wave localization the filamentation 2