The cationic polymerization of cyclopentadiene (CPD) with 1-(4-methoxyphenyl)ethanol (1)/BF3OEt2 initiating system in CH2Cl2:CH3CN 4:1 (v/v) mixture at room temperature and in the presence of water ([H2O]/[BF3OEt2] up to 8) is reported. The number-average molecular weights of obtained polymers increased in direct proportion to monomer conversion or initial monomer concentration (M (n) a parts per thousand currency sign 4,000 g mol(-1)) in agreement with calculated values, and were inversely proportional to initiator concentration. Polymer MWDs were relatively narrow (M (w)/M (n) = 1.4-1.7) up to 60% of monomer conversion. It was also shown that regioselectivity of CPD polymerization with 1/BF3OEt2 initiating system did not depend significantly on water, monomer, or initiator concentration (1,4-structures content was nearly 60% in all cases).