We have synthesized a great number of ternary stannides R2Ni2Sn, R2Pd2+xSn1-x (R = rare earth) and U2M2Sn (M = Fe, Co, Ni, Ru, Rh, Pd, Ir, Pt). They crystallize either in the orthorhombic W2CoB2-type or in the tetragonal U3Si2-type. A structural relationship exists between these types and those of binary RNi and ternary RNiSn or RPdSn equiatomic compounds. Attention is also focused on the wide range of their magnetic properties [complex (B, T)-magnetic phase diagram, antiferromagnetic double right arrow ferromagnetic transition,...]. (C) 1997 Elsevier Science S.A.