Paramagnetic Ni and Pd complexes have been proposed to play an important role in a number of C-C and C-heteroatom bond formation reactions, as well as a series of oxidative and reductive transformations. In this context, a series of uncommon mononuclear Pd(III) complexes have been synthesized and their oxidative reactivity was investigated. In addition, organometallic Ni(III) complexes relevant to cross-coupling reactions have been isolated and their catalytic reactivity was studied in detail. More recently, unique Pd(I) and Ni(I) complexes have been developed, and their reactivity was probed for the first time. Finally, the intermediacy of such paramagnetic Ni and Pd species in several catalytic organometallic reactions will also be discussed.