Superplasticizers (SP) of the “new generation” are essentially polycarboxylate polymers. Polymers of this family can be produced with almost infinite variations in their chemical structure, which allow the fulfilment of specific (tailored) properties. These polymers are more efficient for water reduction and for keeping concrete workability for longer periods. Another class of superplasticizer also available essentially for extreme specifications, is poly(oxyethylen) phosphonates. A few years ago, one objective of superplasticizer development was to produce very robust SPs usable in all types of concrete with limited incompatibilities. It seems now that such a product will probably never exist due to the underlying complexity and variability of cement. More versatile SPs can, however, be obtained by blending different polymers. As the interactions cement/superplasticizer are better understood, tailored SPs for given applications are becoming more readily available. This paper aims at highlighting some key structure-property relationships of these different SPs. The role of the polymer fraction that does not get adsorb onto cement particles is also mentioned.