We study the resonant absorption of fast magnetoacoustic (FMA) waves in inhomogeneous weakly dissipative, isotropic and anisotropic plasmas. The equilibrium states on which the waves are superimposed is static or stationary and are assumed to be in a 1-D planar geometry. The equilibrium model consists of three layers with an inhomogeneous magnetized plasma surrounded by two homogeneous magnetized semi-infinite plasmas. The propagating FMA waves are partly absorbed and partly reflected by coupling to local nonlinear slow magnetohydrodynamic (MHD) waves in the inhomogeneous layer. The dissipation acts only in a narrow layer called thedissipative layerwhich embraces the resonant magnetic surface. In linear theory it has been shown that in the vicinity of the resonant surface the energy density, the amplitudes of waves and the spatial gradients become large, suggesting that in this region nonlinearity might be important. The wave motions far from the dissipative layer are described by the linear, ideal MHD equations, while inside this layer the wave motions are governed by the full system of the dissipative, nonlinear MHD equations. The coefficient of wave energy resonant absorption is derived assuming weak nonlinearity and long-wavelength approximation. ©2000 American Institute of Physics.