Well-established bonding situations of organometallic complexes and extensive applications in synthesis have been achieved during the past 25 years. In contrast, very little attention has been devoted to the intimate understanding of their reaction mechanisms. In this feature article, we show how the combined use of experimental and computational tools can be used to explore some reaction mechanisms of Fischer-type carbene complexes. The results obtained clearly demonstrate the usefulness of these combined tools to unravel the intimacies of different thermal and photochemical transformations, not only to explain already known processes but to predict new reactivity involving these fascinating complexes.