Open-framework zinc phosphates with one-dimensional ladder structures are shown to transform, under simple reaction conditions, to two- and three-dimensional structures. Thus, the one-dimensional ladder, [C₆N₄H₂₂]_0.5[Zn(HPO₄)₂], I, on heating with piperazine in aqueous solution gives a layer phosphate, [C₄N₂H₁₂][Zn₂(PO₄)₂], III, and the three-dimensional phosphates [C₂N₂H₁₀]_0.5[Zn(PO₄)], IV, [C₆N₄H₂₂]_0.5[Zn₂(PO₄)₂], V and [C₆N₄H₂₁]₄[Zn₂₁(PO₄)₁₈], VI. On heating in water in the absence of any amine, I transforms to a three-dimensional solid, [C₆N₄H₂₂]_0.5[Zn₃(PO₄)₂(HPO₄)], VII, with 16-membered channels. Of these, III and IV are the only new compounds. The phosphates formed by the transformations of I exhibit unique structural features. Thus, in III, the layers are formed only with 3- and 4-membered rings and have step-like features due to the presence of infinite Zn–O–Zn linkages. Compound IV has a structure similar to that of the naturally occurring aluminosilicate, gismondine, and VI possesses unusual Zn₇O₆ clusters. The ladder zinc phosphate, [C₃N₂H₁₂][Zn(HPO₄)₂], II, transforms to two layered compounds, [C₃N₂H₁₂][Zn₄(PO₄)₂(HPO₄)₂], VIII, and [C₃N₂H₁₂][Zn₂(HPO₄)₃], IX, on heating with zinc acetate and water, respectively. II, on heating in water in the presence of other amines, forms a ladder, [C₃N₂H₅][Zn(HPO₄)], X, and a three-dimensional phosphate, [C₃N₂H₁₂]₂[Zn₅(H₂O)(PO₄)₄(HPO₄)], XI. The syntheses and structures of VIII–XI have already been reported. What is interesting is that the majority of the transformations seem to occur through the process of deprotonation of the phosphoryl group and elimination of the –HPO₄ unit. The transformations of the ladder phosphates to higher dimensional structures reported in the present study not only demonstrate the seminal role of the one-dimensional structures as basic building units, but also the likely occurrence of self-assembly of these one-dimensional units in the building-up process.