We consider short pulse propagation in nonlinear metamaterials characterized by a weak Kerr-type nonlinearity in their dielectric response. In the frequency "band gaps" (where linear electromagnetic waves are evanescent) with linear effective permittivity ǫ < 0 and permeability µ > 0, we derive two short-pulse equations (SPEs) for the high-and lowfrequency band gaps. The structure of the solutions of the SPEs is also briefly discussed, and connections with the soliton solutions of the nonlinear Schrödinger equation are presented. . The frequency dependence of the effective permittivity ǫ and permeability µ of these media is such that there exist frequency bands where the medium displays either a right-handed (RH) behavior (ǫ > 0, µ > 0) or a left-handed (LH) behavior (ǫ < 0, µ < 0), thus exhibiting negative refraction at microwave [2,3,4] or optical frequencies [5]. Frequency band gaps, i.e., frequency domains where linear EM waves are evanescent (e.g., for ǫ < 0 and µ > 0), also exist in metamaterials. Hence, when a nonlinearity occurs, say in the dielectric response of the medium (a physically relevant situation in nonlinear metamaterials [6,7,8,9,10,11,12]), then nonlinearity-induced localization of EM waves is possible. Such localization is indicated by the formation of gap solitons, which occur mainly in nonlinear optics [13] and Bose-Einstein condensates (BECs) [14], by means of the nonlinear Schrödinger (NLS) equation with a periodic potential. Gap solitons were also predicted to occur in nonlinear metamaterials [15]. There, the approximation of slowly varying electric and magnetic field envelopes, led to a nonlinear Klein-Gordon (NKG) equation supporting gap solitons.Nonlinear models describing localization of wave packets in periodic media, e.g., the NLS equation in optics [13] and NKG equation in metamaterials [15] are usually derived in the framework of the slowly-varying envelope approximation. However, as far as ultra-short pulse propagation is concerned, i.e, for pulse widths of the order of a few cycles of the carrier