Well-defined dendritic oligomers of poly(beta,beta-dibromo-4-ethynylstyrene) of the first and second generation have been synthesized by a stepwise synthesis, and characterized. It was found from n.m.r. analysis and by theoretical calculations that free rotation around formal single bonds is hampered by conjugation. All oligomers were found to be blue emitters with their emission maxima correlating with the number of repeating units. All dendrimers except dendrimer 12 (beta,beta-bis[beta＇,beta＇-di(beta ",beta "-dibromostylyl-4 "-ethynyl)styryl-4＇-ethynyl]-4-ethynylstyrene) showed two maxima in the excitation spectra.