The title heteroleptic neutral cobalt(II) tri-tert-butoxysilanethiolate complexes with monodentate nitrogen bases (L) as additional ligands have been prepared by the reactions of [Co{μ-SSi(O t Bu) 3 }{SSi(O t Bu) 3 }(NH 3 )] 2 (1) with respective bases. For pyridine both types have been prepared - with two (2) or one (3) nitrogen ligand bonded to cobalt(II). [Co{SSi(O t Bu) 3 } 2 (L)] complexes have been obtained also with 2-picoline (5), 2,4-lutidine (6), 3,5-lutidine (7), and [Co{SSi(O t Bu) 3 } 2 (L) 2 ] also with N-methylimidazole (8) and morpholine (9). Molecular and crystal structures of the six compounds have been determined by single-crystal X-ray structural analysis. In 3, 5 and 7 three-coordinated cobalt(II) seems to interact very weakly with two oxygen atoms from two Si(O t Bu) 3 moieties approaching highly distorted trigonal bipyramidal geometry. Compounds 2, 8 and 9 have distorted tetrahedral structures. Both types of complexes gave characteristic electronic spectra, similar within each type.