Solution properties of poly(N-vinylcarbazole) (PVCz) and copolymers of N-vinylcarbazole with methyl methacrylate are investigated by using SEC coupled with differential refractive index (RI), multiangle light scattering (MALS), and UV detectors. The technique affords information on molecular weight, molecular weight distributions, and the chemical composition of copolymers. Moreover, the polymer dimensions are investigated in two different solvents, tetrahydrofuran (THF) and toluene, which are good and poor solvents, respectively, for poly(N-vinylcarbazole). The collapse of the polymer chain, the scaling laws, unperturbed dimensions, and characteristic ratios are determined by employing only a broad polydisperse polymer sample. The results are in good agreement with those obtained by much more complex procedures for the homopolymer PVCz. The influence of the methyl methacrylate content in the dimensions of the copolymer chains is analyzed. Unperturbed dimensions are also calculated employing a simple two-state RIS model. Agreement between calculated and measured values of C-n is excellent for homopolymers and copolymers with contents of MMA units up to ca. 80%.