We report on the synthesis of ruthenium indenylidene catalysts [RuCl2(3-R-1-indenylidene)(PCy3)2inwhich R is iso-propyl (7a), tert-butyl (7b) or cyclohexyl (7c)]. The obtained alkyl tagged indenylidenecatalysts were analyzed by means of IR, elementa l analysis, NMR and single crystal X-Ray diffractionanalysis. Furthermore, the catalytic performance of these new complexes was examined in dif ferentmetathesis reactions: ring-closing metathesis (RCM), ring-closing ene-yne metathesis (RCEYM), ring-opening metathesis polymerization (ROMP) and cross metathesis (CM), exhibiting a comparable activ-ity in comparison with the commercially available catalyst 3a