Crystals of the tau (tau) isoform of the 14-3-3 family of proteins were grown and shown to belong to the orthorhombic space group P2(1)2(1)2(1) with cell dimensions a = 70.29, b = 79.3, c = 101.00 A. The crystals were needle-like in morphology and less than 10 micro m in two dimensions. Diffraction data were collected using synchrotron radiation sources from flash-cooled crystals. Native data extended to a resolution of 2.6 A and mercury and platinum derivatives diffracted to 3.4 and 3.9 A, respectively. The structure has been solved recently. Here the protein crystallization procedures, the characterization of the crystals and the correlation between crystal habit and diffraction quality are reported.