A series of neutral complexes of platinum(II) of general formula [PtCl 2 L(PPh 3 )] [L=Et 2 NC(Me)NH, SOMe 2 , CO, Et 2 NH, (HOCH 2 CH 2 ) 2 NH, Bz 2 NH, N-morpholine] was prepared starting from suitable precursors. The syntheses and spectroscopic characterizations of the two new complexes trans-[PtCl 2 (N-morpholine)(PPh 3 )] and cis-[PtCl 2 (SOMe 2 )(PPh 3 )] are described as well as their X-ray structures. The antiproliferative activity of all the available compounds was tested in vitro against HeLa, H460 and A549 human tumor cell lines. A brief discussion regarding the structure–activity correlation is presented.