The anionic polymerization of 1,3-cyclohexadiene (1,3-CHD) using various initiating systems and with or without additives was studied. In contrast to the situation with linear conjugated dienes, common anionic initiators in the absence of additives fail to produce poly(1,3-cyclohexadiene) (PCHD) with controlled molecular weight (MW) and narrow molecular weight distribution (MWD) because of side reactions. However, certain additives change the nature of the polymerization dramatically. Monodentate additives do not yield controlled polymerization, while some polydentate additives, such as N,N,N',N'-tetramethylethylenediamine (TMEDA), 1,2-dimethoxyethane (DME), and 1,4-diazabicyclo[2.2.2]octane (DABCO), are effective in minimizing side reactions, if combined with the suitable butyllithium isomer. For example, the synthesis of PCHD samples with narrow MWD and good MW control is possible using the n-BuLi/DME/0 degreesC or sec-BuLi/DABCO/20 degreesC in benzene. The "living" character of these polymerizations is discussed.