Rv1698 has been reported to be an important outer membrane channel protein of Mycobacterium tuberculosis with unknown function. Recombinant Rv1698 overexpressed in Escherichia coli was purified in detergent solution and crystallized at 295 K using the sitting-drop vapour-diffusion method with ammonium sulfate as a precipitant. The crystals of Rv1698 diffracted to 2.5 Å resolution and belonged to the orthorhombic space group P422, with unit-cell parameters a = b = 122.0, c = 88.9 Å.