The ratios of the intensity of excimer and monomer emissions, denoted I-E/I-M in poly(N-vinyl carbazole) and copolymers of N-vinyl carbazole and methyl methacrylate were measured with steady-state fluorescence. Measurements were performed in dilute solutions of several fluid solvents at 25 degreesC and in a solid matrix of poly(methyl methacrylate) at room temperature. The values of I-E/I-M, depended on tile nature of the solvent, the emission wavelength, and the copolymer composition. Molecular dynamics simulations were performed for diastereoisomers of 2,4-di(N-carba-zolyl)pentane and for isotactic and syndiotactic trichromophoric copolymer fragments to assist in the identification of the thermally accessible conformations capable of forming intramolecular excimers and the configurational relationship of the carbazole units in these complexes. Nearest neighbor carbazole groups made the dominant contribution to the excimers. Excimers were more likely in isotactic sequences than in syndiotactic sequences, as was also the case for the low-energy excimer arising fi om tile complete overlap of two carbazole units.