A unique pressure‐induced Cu−N bond breaking/bond forming reaction is reported. The variation of pressure on a single crystal of a one‐dimensional copper‐ (II)‐containing coordination polymer (Cu2L2(1‐methylpiperazine)2]n, where H2L is 1,1′‐(1,3‐phenylene)‐bis(4,4‐dimethylpentane‐1,3‐dione)), was monitored using single crystal X‐ray diffraction with the aid of a diamond anvil cell. At a very low elevated pressure (≈0.05 GPa) a remarkable reversible phase change was observed. The phase change results in the depolymerization of the material through the cleavage and formation of axial Cu−N bonds as well as “ring flips” of individual axially coordinated 1‐methylpiperazine ligands. Overall, the pressure‐induced phase change is associated with a surprising (and non‐intuitive) shift in structure‐from a 1‐dimensional coordination polymer to a discrete dinuclear complex.