Transmetalation of a dimeric homotrinuclear zinc(II) complex [(3-MeOsalamo)(2)Zn-3] with Lu3+ and La3+ afforded heterometallic dinuclear [(3-MeOsalamo)ZnLu](3+) and trinuclear [(3-MeOsalamO)(2)Zn2La](3+) complexes, respectively, whose structures were determined by X-ray crystallography. The transmetalation process was investigated by (HNMR)-H-1 titrations.