The present study describes the quantitative monitoring of the metallocene-catalyzed copolymerization of propene with 10-undecene-1-ol (UO) by in-line ATR-FTIR spectroscopy in order to obtain kinetic data. For the description of the time dependency of this copolymerization reaction a pseudo-first-order rate law was used. The apparent rate constant k(app) of the comonomer consumption could be determined by evaluation of the integral absorbances of characteristic IR bands of the double bond of UO and of special IR determined concentration profiles of that comonomer using chemometric tools. The apparent rate constants determined by the integral absorbances of the v C=C band (stretching vibrations) range or 0.32-0.66 x 10(-4) s(-1) whereas evaluation of the absolute concentrations of the comonomer yields rate constants of 0.29-0.57 x 10(-4) s(-1). Variations within the rate constants obtained from different experimental runs point to a certain complexity of the reaction and a significant dependence of the copolymerization on the exact polymerization procedure.