Recent developments in cobalt-mediated radical polymerization (CMRP) and progress in the mechanistic understanding enabled to optimize the copolymerization of n-butyl acrylate (nBA) with vinyl acetate (VAc), as well as to control the hornopolymerization of nBA by means of bis(acetylacetonato)cobalt-(II) (Co(acac)(2))- Critical experimental parameters such as the initiating system, the temperature, and the presence of additives were varied and discussed. Under optimized conditions, an alkylcobalt(III) adduct R-0-(CH2-CHOAc)(<4)-CO(acac)(2) (R-0 = primary radical from the V-70 decomposition) allowed a better control of the nBA/VAc copolymerization than the previously studied V-70/CO(acac)(2) pair regarding the molecular weight control and the polydispersities. Importantly, the homopolymerization of nBA was controlled by Co(acac)(2) for the first time using the alkylcobalt(III) adduct or the lauroyl peroxide (LPO)/Co(acac)(2) redox pair as initiating system. Typically, poly(n-butylacrylate) with polydispersity around 1.2 and molar mass as high as 200 000 g/mol was achieved with this cobalt complex.