The ring opening metathesis polymerization (ROMP) of cycloocta-1,5-diene (COD) is mediated by a series of six well-defined ruthenium-based indenylidene catalysts. The polymerization kinetics are monitored and compared with three generations of Grubbs’ catalyst. Moderate control over the polymerizations was observed for both benzylidene and indenylidene-based catalysts.