In this review paper, we discuss the influence of weak quenched disorder on the critical behavior in condensed matter and give a brief review of available experimental and theoretical results as well as results of MC simulations of these phenomena. We concentrate on three cases: (i) uncorrelated random-site disorder, (ii) long-range-correlated random-site disorder, and (iii) random anisotropy.Today, the standard analytical description of critical behavior is given by renormalization group results refined by resummation of the perturbation theory series. The convergence properties of the series are unknown for most disordered models. The main object of this review is to discuss the peculiarities of the application of resummation techniques to perturbation theory series of disordered models.In contrast to the critical temperature, the values of the critical exponents do not depend on microscopic details of the Hamiltonian and are determined only by the global properties of the model. For a short-range interaction the global properties are the lattice dimension d, the dimension m and other symmetry properties of the order parameter. Due to the fact that the critical exponents may be identical November 9, 2018 10:37 WSPC/Guidelines lecture Weak quenched disorder and criticality: resummation of asymptotic(?) series 5