We have performed a renormalization group analysis of the tricritical behavior of dilute polymer solutions containing quenched impurities in three dimensions. We have treated the quenched disorder using the replica formalism. The logarithmic corrections to the mean field results for the quenched problem are found to be in a different universality class from those for the pure or annealed problem. For example, the leading corrections to the second virial coefficient and the specific heat are proportional to L1/2(ln L/a0)−2/11 and L(ln L/a0)7/11, respectively, where L is the chain length and a0 is the cutoff; the coexistence curve is found to follow the universal equation u∼−𝒞(‖ln 𝒞2a0‖)−9/11 when 𝒞2a0≪1, where 𝒞 is the monomer concentration and u is the two-body excluded volume interaction parameter.