Diaquacobalt(II) n‐dodecane‐α,ω‐dioate (2) has been synthesized by metathesis of the corresponding potassium soap 1 and has been fully characterized by chemical and spectroscopic analysis. The crystal structure of 2 has been established by X‐ray powder diffraction techniques combined with electron diffraction experiments. It crystallizes in a monoclinic cell [P2₁/a; a = 9.6558(8), b = 7.4793(6), c = 19.8936(2) Å, β = 95.648(9)°, V = 1429.7(3) ų; Z = 2] and consists of stacked layers of cobalt(II) ions connected by carboxylato bridges, thus forming chains that extend along the a axis. These layers are separated by alkyl chains arranged quasi‐perpendicularly to the polar sheets. Structure analysis reveals a rare anti‐anti conformation of the Co−OCO−Co fragments, which is thought to be responsible for the weak antiferromagnetism of the Co^II chains. The exchange coupling constant between the magnetic centres has been estimated as J = −2.08 K.