We analyze the first-order nonspecular effects of three-dimensional beams in interfaces formed by two lineal dielectric media. We also analyze the dependence of the transverse effects on polarization and compare the results with those obtained for isotropic interfaces. In particular, we determine analytically the complex transverse lateral displacements of a beam with Gaussian distribution of intensity when it is reflected on an interface formed by an isotropic medium and a uniaxial anisotropic one and the mean direction of propagation of the beam is contained in each of the characteristic planes of the crystal.