An attempt is made to develop a law of the wall for a thick axisymmetric turbulent boundary layer in which the sublayer thickness is comparable to the radius of transverse curvature. Examination of the equations of motion in the viscous sublayer suggests a law similar to that in two-dimensional flow. Available experimental information is consistent with this law, but the structure of turbulence in such thick axisymmetric boundary layers would seem to need further study.