To summarize, we have successfully synthesized and structurally characterized a rare quaternary phase Eu2Mn0.89Cd1.11Pt2 with the LaNiAl type, which realizes a blend of the structural features of the two ubiquitous TiNiSi and ZrNiAl structure types in one single crystal structure. An unexpected partial ordering of isovalent Cd(d 10 ) and Mn(d 5 ) atoms may be the main factors behind the stability of this phase, while the elusive Cd-free end member "EuMnPt" is most likely non-existent. Eu2Mn0.89Cd1.11Pt2 contains high magnetic moment on paramagnetic f-metal Eu 2+ and d-metal Mn 2+ , and may be prone to couple structural and magnetic phase transition, which will qualify it as a potential candidate to exhibit strong magnetocaloric effects.