Reaction of the inversely polarized phosphaalkene HP=C(NMe2)2 (1) with AuCl(PPh3) (2a) in a molar ratio of 2:1 in THF led to the formation of complex Au{HP=C(NMe2)2}2Cl (3) as a pale yellow solid. In contrast to this, treatment of 2a with two molar equivalents of tBuP=C(NMe2)2 (4) afforded a mixture of Au{P(tBu)=C(NMe2)2}2+Cl− (5) and {(Me2N)2C=(tBu)PAu}2(μ‐Cl)+Cl− (6). In CH2Cl2 solution this mixture was slowly converted into the novel decanuclear complex Au8(AuCl)2{μ3‐P(tBu)}2{μ‐P(tBu)=C(NMe2)2}64+(Cl−)4 (7) featuring six edge‐bridging phosphaalkene ligands and two μ3‐tert‐butylphosphanediide ligands. In solution the cluster 7 shows a high order 31P{1H} NMR spectrum of the AB2C2 type. According to the X‐ray structural analysis the Au10 framework may be described as a slightly puckered ladder constructed of three quadrangles. The central Au4 parallelogram is capped on both faces by a pair of tBuPAuCl units. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)