Creatine kinase (CK; E.C. 2.7.3.2) is an important enzyme that catalyzes the reversible transfer of a phosphoryl group from ATP to creatine in energy homeostasis. The brain-type cytosolic isoform of creatine kinase (BB-CK), which is found mainly in the brain and retina, is a key enzyme in brain energy metabolism, because high-energy phosphates are transfered through the creatine kinase/phosphocreatine shuttle system. The recombinant human BB-CK protein was overexpressed as a soluble form in Escherichia coli and crystallized at $22^{circ}C$ using PEG 4000 as a precipitant. Native X-ray diffraction data were collected to $2.2{AA}$ resolution using synchrotron radiation. The crystals belonged to the tetragonal space group $P4_32_12$, with cell parameters of a=b=97.963, $c=164.312{AA},;and;{alpha}={eta}={gamma}=90^{circ}$. The asymmetric unit contained two molecules of CK, giving a crystal volume per protein mass $(V_m)$ of $1.80{AA}^3;Da^{-1}$ and a solvent content of 31.6%.